Can tail emmision be a soft fork

[vjudeu]

Plus what's the problem with millisats?

The main problem is that they disappear, when you want to go on-chain. So, if you have a lot of users, and everyone owns 999 millisatoshis, then those coins can exist only in LN, and then you cannot go on-chain without losing them. But as I said, we are still far away from that.

But because satoshi is the smallest unit that matters on-chain, you have for example default fees of 1000 millisatoshis, and many amounts don't use those additional decimal places, because they are lost when going on-chain, so people don't want to end up with any non-zero amounts on those last three digits, because if you have a lot of them, then those coins are effectively worthless outside LN.

That shouldn't actually count as a "new consensus rule", no?

Why not? This example can clearly show you, that even if some feature is not supported on-chain at all, you can still introduce it on some second layer, and leave it there. And this approach has its good and bad sides. The good news is that you can experiment, and introduce for example mining inside LN, and receive even single millisatoshis for the work done by your CPU through merged-mining. The bad news is that if something is not enforced on-chain, it is not fully used, as long as this support is missing. And then, technically you can have working millisatoshis, but practically everyone still count things in satoshis, and make sure to clear all additional features, just to be compatible with the first layer.

So, going back to the topic: Can tail supply be a soft fork? Yes, it definitely can. And if you use LN, then it can even be a no-fork, exactly in the same way as millisatoshis are. Because it is perfectly valid to form a network similar to LN, where instead of adding additional precision, you can print additional coins, and turn 21 million coins limit into 21 billion coins limit. Of course, the market will react accordingly, but technically you can make some LN-like network with tail supply, and test how many people will support it. And you can adjust the numbers to make it better than 1000x supply increase.

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[NotATether]

Plus what's the problem with millisats?

The main problem is that they disappear, when you want to go on-chain. So, if you have a lot of users, and everyone owns 999 millisatoshis, then those coins can exist only in LN, and then you cannot go on-chain without losing them. But as I said, we are still far away from that.

But because satoshi is the smallest unit that matters on-chain, you have for example default fees of 1000 millisatoshis, and many amounts don't use those additional decimal places, because they are lost when going on-chain, so people don't want to end up with any non-zero amounts on those last three digits, because if you have a lot of them, then those coins are effectively worthless outside LN.

You can solve the problem of losing stray millisats by including then in the fee sent to the lightning router when you close the channel.

[Wind_FURY]

Plus what's the problem with millisats?

The main problem is that they disappear, when you want to go on-chain. So, if you have a lot of users, and everyone owns 999 millisatoshis, then those coins can exist only in LN, and then you cannot go on-chain without losing them. But as I said, we are still far away from that.

But because satoshi is the smallest unit that matters on-chain, you have for example default fees of 1000 millisatoshis, and many amounts don't use those additional decimal places, because they are lost when going on-chain, so people don't want to end up with any non-zero amounts on those last three digits, because if you have a lot of them, then those coins are effectively worthless outside LN.

But it doesn't merely disappear into thin air, no? I believe someone in BitcoinTalk said the millisats go to the channel peer when a user closes the channel, and the peer's coins are rounded up to the nearest Satoshi when they settle in the Bitcoin blockchain.

That shouldn't actually count as a "new consensus rule", no?

Why not? This example can clearly show you, that even if some feature is not supported on-chain at all, you can still introduce it on some second layer, and leave it there. And this approach has its good and bad sides. The good news is that you can experiment, and introduce for example mining inside LN, and receive even single millisatoshis for the work done by your CPU through merged-mining. The bad news is that if something is not enforced on-chain, it is not fully used, as long as this support is missing. And then, technically you can have working millisatoshis, but practically everyone still count things in satoshis, and make sure to clear all additional features, just to be compatible with the first layer.

OK, I understand your viewpoint. But technically onchain where it truly matters and where the consensus rules are enforced, there are no rule changes.

So, going back to the topic: Can tail supply be a soft fork? Yes, it definitely can. And if you use LN, then it can even be a no-fork, exactly in the same way as millisatoshis are. Because it is perfectly valid to form a network similar to LN, where instead of adding additional precision, you can print additional coins, and turn 21 million coins limit into 21 billion coins limit. Of course, the market will react accordingly, but technically you can make some LN-like network with tail supply, and test how many people will support it. And you can adjust the numbers to make it better than 1000x supply increase.

There's no "tail supply" when the accounting adds millisats in Lightning. Everything still adds to 21,000,000 Bitcoins. IE it still adds to one pizza even though the slices are made smaller. Nothing was printed from thin air.

[BlackHatCoiner]

So, going back to the topic: Can tail supply be a soft fork? Yes, it definitely can. And if you use LN, then it can even be a no-fork, exactly in the same way as millisatoshis are. Because it is perfectly valid to form a network similar to LN, where instead of adding additional precision, you can print additional coins, and turn 21 million coins limit into 21 billion coins limit.

But, as you covered at the start of your post, they won't really exist. Just as with 999 millisat, they only exist as long as we're in lightning. The moment you want to withdraw 1999 millisat, 999 millisat are rounded down to zero.

It might work, but the sub-network will look like a fractional reserve system, where 1 BTC will be inflated as long as it stays in that sub-network, and the participants must remain in that network and not withdraw to main layer.

You can solve the problem of losing stray millisats by including then in the fee sent to the lightning router when you close the channel.

Millisats aren't lost in the sense that they disappear. It's just 1 sat changing hands. If you have 999 millisat outgoing in a channel, then closing it will mean you get to take the ~1 sat. Either rounding it down or up, someone is just taking a little bit more.

[Wind_FURY]

So, going back to the topic: Can tail supply be a soft fork? Yes, it definitely can. And if you use LN, then it can even be a no-fork, exactly in the same way as millisatoshis are. Because it is perfectly valid to form a network similar to LN, where instead of adding additional precision, you can print additional coins, and turn 21 million coins limit into 21 billion coins limit.

But, as you covered at the start of your post, they won't really exist. Just as with 999 millisat, they only exist as long as we're in lightning. The moment you want to withdraw 1999 millisat, 999 millisat are rounded down to zero.

Don't the millisats go to the channel peer? Therefore the channel closer gets his sats rounded down, and the peer gets his sats rounded up in the Bitcoin blockchain?

It might work, but the sub-network will look like a fractional reserve system, where 1 BTC will be inflated as long as it stays in that sub-network, and the participants must remain in that network and not withdraw to main layer.

But there was nothing inflated by implementing millisats. 1 BTC still equals to 1 BTC in Lightning because it merely added decimal places going down. Adding decimal places won't make 1 BTC = 1.000000000001 BTC, no? Or am I wrong in my understanding how Lightning works?

[BlackHatCoiner]

Don't the millisats go to the channel peer? Therefore the channel closer gets his sats rounded down, and the peer gets his sats rounded up in the Bitcoin blockchain?

Suppose I share a channel with you. I have 1,000,000,999 millisat in outgoing liquidity. That means this is the maximum amount I can send you (minus some small percentage of the amount which cannot be spent, to disincentivize fraud). If I close the channel, I'll get 0.01 BTC. You would get to keep the 1 sat; I would take it if I had earned 1 more millisat.

But there was nothing inflated by implementing millisats. 1 BTC still equals to 1 BTC in Lightning because it merely added decimal places going down. Adding decimal places won't make 1 BTC = 1.000000000001 BTC, no? Or am I wrong in my understanding how Lightning works?

No, you're right. But, read vjudeu's post:

Can tail supply be a soft fork? Yes, it definitely can. And if you use LN, then it can even be a no-fork, exactly in the same way as millisatoshis are. Because it is perfectly valid to form a network similar to LN, where instead of adding additional precision, you can print additional coins, and turn 21 million coins limit into 21 billion coins limit.

I can't imagine the design of such a network, but from my understanding, there must be no going back in the main layer, because if everyone wanted to withdraw their new-BTC, they'd have to be less than 21 million in total.

[vjudeu]

there must be no going back in the main layer, because if everyone wanted to withdraw their new-BTC, they'd have to be less than 21 million in total

Why you want to block going back into the main layer? If you want to make a connection in a single direction, then you can just burn mainchain coins, and it would be much easier to deploy. Tracing all coins inside OP_RETURN, and making an altcoin out of that is easy.

Going back is possible. But then, it wouldn't be just 1:1 peg (or more precisely, 1:1000 peg, as it is in LN), but the proportions will be different, and will depend on how many coins will be added. So, if you would have 42 million coins, then it would mean just 1:2 peg (or, you can just use LN with 500 millisatoshis granularity, and reach the same outcome, the only different thing will be the ownership of those coins).

Edit: Maybe that would help you: if you don't have millisatoshis, you have constant 1:1 peg. If you have millisatoshis, you have constant 1:1000 peg. If you have tail supply, you start from 1:1 peg, but it becomes 1:2, 1:3, and 1:N peg over time. Or maybe, more realistically: 1,000,000:1,000,001, then 1,000,000:1,000,002, and so on. But there is still a peg, and even if you won't create any, then it would be a similar situation as with altcoins, where you would have centralized parties in between, like exchanges, when you swap between those coins.

[BlackHatCoiner]

So, if you would have 42 million coins, then it would mean just 1:2 peg (or, you can just use LN with 500 millisatoshis granularity, and reach the same outcome, the only different thing will be the ownership of those coins).

Then, that is not inflation. If you create a new network, where people can exchange BTC for new-BTC, then that'd be an altcoin. Or rather, if to create new-BTC you must lock BTC, then that's sort of a sidechain. Inflation is when there is more money supply. If people suddenly wanted to use a centralized exchange as Bitcoin wallet, and that implemented fractional reserve, then the total bitcoin would increase, as now the total money would have to include checkable deposits. (It has happened with FTX)

Pegs aren't counted as more money supply. If you need to lock BTC to get new-BTC, then no money has been created. To have new-BTC you need to temporarily make the BTC unusable, you're just exchanging value between networks.

If you have tail supply, you start from 1:1 peg, but it becomes 1:2, 1:3, and 1:N peg over time.

That's inflation for the sidechain coin and deflation for bitcoin. If overtime the withdrawal amount in the main layer shrinks, then that means new-BTC loses value in comparison with BTC overtime.

[vjudeu]

That's inflation for the sidechain coin and deflation for bitcoin.

You understand it correctly. If tail supply will be deployed in any way you want (hard-fork, soft-fork, no-fork, sidechain, whatever), that would mean BTC-with-tail-supply will have more inflation than BTC-without-tail-supply. Which means that Not Surprisingly, Tail Emission is Inflationary, and a lot of people wrote well about it, including this topic on bitcointalk.

[JayJuanGee]

Since you guys are talking so much about milli-satoshis and also the idea of being able soft fork for the purposes of a tail emmission, I just keep wondering about the idea sub-satoshi digits being recognized, and it seems to me that tail emissions could already be built into bitcoin, "as is" except for the seemingly mere fact that the code does not recognize less than a satoshi units... so why not just add another 3-8 digits to the recognition on the main blockchain, and then just continue to have halvenings (blockrewards) forever. 

Why can't something like that work?  I am pretty sure that I asked the question before, and I am pretty sure that the answer was merely based on the satoshi being the smallest unit recognized and therefore there is no recognition of rewards (splits) that happen below those 8 digits, once the number of digits starts to get down to that level.. .. and right now we are only going from 6.25 to 3.125 (2 digits after the decimal to 3 digits

2024  = 3.125  (3 digits)

2028  = 3.5625  (4 digits)

2032  = 0.78125  (5 digits)

2036  = 0.390625  (6 digits)

2040  = 0.1953125  (7 digits)

2044  = 0.09765625  (8 digits)

2048  = 0.048828125  (9 digits)   or 0.04882812  (8 digits)

My understanding is that right now the current bitcoin software variations do not recognize beyond 8 digits, so in 2048 the 9th digit is not going to be recognized, so it gets cut off.. but why not just continue to recognize infinite digits.. that recognition of further digits beyond 8 digits is not creating more bitcoin and/or satoshis beyond the original contemplation, so the total will never go above 21 million even though the recognition will continue to go to smaller and smaller subunits. in order to have the halvening and the reward forever.. even though the smaller units might not be worth much of anything.. but that seems to be a question for the future rather than the present... but such recognition of more than 8 digits does seem to be affected in the current reward set-up starting in 2048.. and to me it seems like it could be a soft fork to merely add further recognition of bitcoin of smaller values than a satoshi (or with more than 8 digits after the decimal).

[vjudeu]

but why not just continue to recognize infinite digits

You can. But then, all overprinted coins should be backward-compatible. Which means, it doesn't matter if you create a single additional satoshi, or if you want to double the supply. The code for both cases will be similar, and will require mapping the supply, by using appropriate proportions. In this case, you will have it mapped in 20,999,999,9769,0000 : 21,000,000,0000,0000 constant proportions (while in LN, you have for example 1:1000 constant proportions).

Edit: More than that. I guess in the future we will see some altcoins, where Bitcoin miners could receive altcoin rewards, and get those fractional satoshis, halved "ad infinitum". But then, the exchange rate may be worse than 20,999,999,9769,0000 : 21,000,000,0000,0000 between Bitcoin, and such altcoin, unless you will have some decentralized two-way peg. Many people thought about infinite halvings before, but in the old times, if they wanted that, they often did hard forks, and then their altcoins became worthless. For example, there was a hard-fork, that disabled all halvings, and where altcoiners could get 50 ALTs "ad infinitum". But of course it died, and altcoins with infinite halvings will also die, unless someone will design them carefully, to reach a peg, and maintain it on a similar level as in Lightning Network.

[tromp]

I just keep wondering about the idea sub-satoshi digits being recognized, and it seems to me that tail emissions could already be built into bitcoin, "as is" except for the seemingly mere fact that the code does not recognize less than a satoshi units... so why not just add another 3-8 digits to the recognition on the main blockchain, and then just continue to have halvenings (blockrewards) forever.  

A tail emission is an everlasting *fixed* block subsidy, that keeps on growing the supply beyond bound, and that guarantees a minimum level of security regardless of fees.

Adding digits forever to spread out the last 210000 satoshis (i.e. 2.1 mBTC) of supply over infinitely many blocks is *NOT* a tail emission. It's just pointlessly wasting bandwidth on unnecessary precision.

[vjudeu]

Adding digits forever to spread out a the last 210000 satoshis (i.e. 2.1 mBTC) of supply over infinitely many blocks is *NOT* a tail emission.

True, which means there are more chances to get it implemented. Because it is a difference between constant peg, and volatile peg. If you have Lightning Network, you have 1:1000 peg. It is fine. In "infinite halvings" model, you have constant 20,999,999,9769,0000 : 21,000,000,0000,0000 peg. This is also fine. In "tail supply", you start from 1:1 peg, but it is volatile, and it is changed by each and every overprinted satoshi, first from 20,999,999,9769,0000 : 20,999,999,9769,0001, and then the denominator is just incremented with each satoshi, created by "tail supply" supporters.

But anyway, it does not affect implementation that much. You could have "burn supply", instead of "tail supply" as well, and start from 20,999,999,9769,0000 : 20,999,999,9768,9999, and then decrease your denominator with each and every burned satoshi. That kind of consensus could work as well. Which means, if you can implement a constant peg, you probably can also implement any other volatile peg, because the whole implementation will be very similar, you will just change the exchange rate between the layers.

[JayJuanGee]

I just keep wondering about the idea sub-satoshi digits being recognized, and it seems to me that tail emissions could already be built into bitcoin, "as is" except for the seemingly mere fact that the code does not recognize less than a satoshi units... so why not just add another 3-8 digits to the recognition on the main blockchain, and then just continue to have halvenings (blockrewards) forever.

A tail emission is an everlasting *fixed* block subsidy, that keeps on growing the supply beyond bound, and that guarantees a minimum level of security regardless of fees.

Adding digits forever to spread out the last 210000 satoshis (i.e. 2.1 mBTC) of supply over infinitely many blocks is *NOT* a tail emission. It's just pointlessly wasting bandwidth on unnecessary precision.

I am already questioning your presumption that extra digits beyond a satoshi would not have extra value, even though I can understand why infinite digits might not be a good place to stop, but instead attempt to figure out some number of digits (currently at 8 on chain and then 11 digits if we are referring to lightning network).

So it is difficult to presume in advance how far to go with the number of digits before they would not have value.. so maybe there is a need to ONLY go to 8 digits right now, but add another 8 digits every 32 years (that is 8 x 4) .. and if the extra digits do not have any value, then I can see the point that they are just taking up space, but I am having difficulties seeing the point of not being precise when we are not sure how much value sub-satoshis are going to have or how many digits we might need to go at any particular time before no more value is present. 

It seemed to me that ONLY one digit would need to be added every 4 years. but I suppose if we are considering backwards and forwards compatibility then there might need to be some kind of a forward projection of value (and/or considerations regarding how many digits to go in order to project out)..

In that regard, it seems that already on the lightning network, there has been some considerations that 1/1000 of a satoshi does have some value... and so by the time we start getting into more than 8 digit bitcoin block rewards in 2048 (as I pointed out in my earlier post), then at that point there likely would be some further needs for subsatoshis even going beyond three additional digits beyond the satoshi that the lightning network already shows.

I am starting to like my idea of adding 8 more digits every 32 years.. but then when to start?.. To me it seems that there would be some kind of a need to start prior to their being recognized in the block reward... but surely I can appreciate that at some point bitcoin is likely NOT going to be going up in value enough in order to justify adding more digits (or worthless bandwith consumption precision, as you suggested).

[Wind_FURY]

Since you guys are talking so much about milli-satoshis and also the idea of being able soft fork for the purposes of a tail emmission, I just keep wondering about the idea sub-satoshi digits being recognized, and it seems to me that tail emissions could already be built into bitcoin, "as is" except for the seemingly mere fact that the code does not recognize less than a satoshi units... so why not just add another 3-8 digits to the recognition on the main blockchain, and then just continue to have halvenings (blockrewards) forever. 

Why can't something like that work?  I am pretty sure that I asked the question before, and I am pretty sure that the answer was merely based on the satoshi being the smallest unit recognized and therefore there is no recognition of rewards (splits) that happen below those 8 digits, once the number of digits starts to get down to that level.. .. and right now we are only going from 6.25 to 3.125 (2 digits after the decimal to 3 digits

2024  = 3.125  (3 digits)

2028  = 3.5625  (4 digits)

2032  = 0.78125  (5 digits)

2036  = 0.390625  (6 digits)

2040  = 0.1953125  (7 digits)

2044  = 0.09765625  (8 digits)

2048  = 0.048828125  (9 digits)   or 0.04882812  (8 digits)

My understanding is that right now the current bitcoin software variations do not recognize beyond 8 digits, so in 2048 the 9th digit is not going to be recognized, so it gets cut off.. but why not just continue to recognize infinite digits.. that recognition of further digits beyond 8 digits is not creating more bitcoin and/or satoshis beyond the original contemplation, so the total will never go above 21 million even though the recognition will continue to go to smaller and smaller subunits. in order to have the halvening and the reward forever.. even though the smaller units might not be worth much of anything.. but that seems to be a question for the future rather than the present... but such recognition of more than 8 digits does seem to be affected in the current reward set-up starting in 2048.. and to me it seems like it could be a soft fork to merely add further recognition of bitcoin of smaller values than a satoshi (or with more than 8 digits after the decimal).

Wouldn't that be just "with the presumption" that a Satoshi would be worth at least a Dollar/near a Dollar? What value would that bring to the miners if a tail-emmission or an inflationary model, assuming it could get community consensus, would better incentivize the miners, immediately, after the fork?

Adding digits forever to spread out a the last 210000 satoshis (i.e. 2.1 mBTC) of supply over infinitely many blocks is *NOT* a tail emission.

True, which means there are more chances to get it implemented. Because it is a difference between constant peg, and volatile peg. If you have Lightning Network, you have 1:1000 peg. It is fine. In "infinite halvings" model, you have constant 20,999,999,9769,0000 : 21,000,000,0000,0000 peg. This is also fine. In "tail supply", you start from 1:1 peg, but it is volatile, and it is changed by each and every overprinted satoshi, first from 20,999,999,9769,0000 : 20,999,999,9769,0001, and then the denominator is just incremented with each satoshi, created by "tail supply" supporters.

Are you sure about that? That requires a hard fork, no?

[BlackHatCoiner]

You understand it correctly. If tail supply will be deployed in any way you want (hard-fork, soft-fork, no-fork, sidechain, whatever), that would mean BTC-with-tail-supply will have more inflation than BTC-without-tail-supply.

Which is my point. BTC-without-tail-supply, which is the current currency, cannot be inflated in a no-fork way.

But why not just continue to recognize infinite digits..

Because that would probably break a lot of software, and either implemented via softfork or hardfork, there will be bad consequences. Turn your question the other way around: why should there be infinite digits? Clearly, 1 sat is of little value, and it will probably be of little value in a couple of decades as well. Even if 1 BTC = $1M, 1 sat is still only worth $0.01.

[vjudeu]

Are you sure about that? That requires a hard fork, no?

Why do you think that Lightning Network with 1:1000 peg requires no hard fork, but 20,999,999,9769,0000 : 21,000,000,0000,0000 peg would suddenly require it? It is all about proportions, nothing more, nothing less. If they are constant, it is as good as inside LN. If they are volatile, then you can reach "tail supply", or "burn supply", it depends if you increase your numerator, or your denominator in "numerator : denominator" peg.

[JayJuanGee]

But why not just continue to recognize infinite digits..

Because that would probably break a lot of software, and either implemented via softfork or hardfork, there will be bad consequences. Turn your question the other way around: why should there be infinite digits? Clearly, 1 sat is of little value, and it will probably be of little value in a couple of decades as well. Even if 1 BTC = $1M, 1 sat is still only worth $0.01.

You may well be correct, and maybe even the milli-satoshi on the lightning network is not necessary or helpful, even though it seems that some people already had decided to add such feature because they thought that it might be useful to add an additional three digits in order to divide satoshis into 1,000 pieces.

So sure, maybe I took it too far... but surely starting in 2048, all of the digits of the block reward are not going to be recognized if the current system stays at ONLY recognizing 8 digits instead of the 9 digits that would be needed to recognize all of the block reward, and every 4 years an additional digit would be needed merely to recognize the block reward.. but yeah, if it clearly does not have any value, then sure, maybe it is not a problem to fail/refuse to recognize any digits beyond the current 8 that are recognized on chain.. and the 11 that are recognized off chain, but those recognition of 11 digits off chain would not affect onchain, unless onchain started to recognize more digits.

I don't presume to know the answer for sure, but it does seem that with the passage of time, that bitcoin is likely going to continue to go up in value (designed to pump forever), so it seems that there could be some justificiation in terms at least minimally recognizing the block rewards all the way down to the proper number of digits, which would mean starting to add one additional digit every 4 years starting in 2048.

Since you guys are talking so much about milli-satoshis and also the idea of being able soft fork for the purposes of a tail emmission, I just [edited out]

Wouldn't that be just "with the presumption" that a Satoshi would be worth at least a Dollar/near a Dollar? What value would that bring to the miners if a tail-emmission or an inflationary model, assuming it could get community consensus, would better incentivize the miners, immediately, after the fork?

I did not consider anything that I was saying to be related exactly to what dollar value that the satoshi might have, but sure there is a bit of a presumption that if more digits are needed, then the sub-units represented by those extra digits would likely need to have some kind of a value. .even if only fractions of a penny, just like a satoshi is fractions of a penny currently yet some folks using the lightning network believe that there is some kind of value in terms of adding three more digits to recognize 1/1000 of a satoshi, even though that is currently pretty damned small values in terms of current dollars.. and so yeah, the less valuable the units representing the further digits down, then the addition of digits might not be necessary and merely taking up band-with (space) as vjudeu had mentioned... so I suppose that there is a bit of a presumption that the dollar value of bitcoin, satoshis, milli-satoshis and any further digits added thereafter are going to go up sufficiently in order to justify their being represented, and that was part of the reason I mentioned adding 8 more digits every 32 years to merely make sure that the mining rewards are accurately depicted.. but at the same time, if those micro-units further down do not really have any value, then even my proposal to add 8 more digits every 32 years may well not be something that is worth putting into practice.

[BlackHatCoiner]

You may well be correct, and maybe even the milli-satoshi on the lightning network is not necessary or helpful, even though it seems that some people already had decided to add such feature because they thought that it might be useful to add an additional three digits in order to divide satoshis into 1,000 pieces.

I presume the reason it exists in lightning, is that the 1 satoshi must be cut in several pieces, because nodes charging 0 sat base fee are attractive, and need to find an income elsewhere (i.e., variable fee). Transaction fees can sometimes be even 1 satoshi, so it's reasonable to have more flexibility with units.

[JayJuanGee]

You may well be correct, and maybe even the milli-satoshi on the lightning network is not necessary or helpful, even though it seems that some people already had decided to add such feature because they thought that it might be useful to add an additional three digits in order to divide satoshis into 1,000 pieces.

I presume the reason it exists in lightning, is that the 1 satoshi must be cut in several pieces, because nodes charging 0 sat base fee are attractive, and need to find an income elsewhere (i.e., variable fee). Transaction fees can sometimes be even 1 satoshi, so it's reasonable to have more flexibility with units.

Surely I am not going to claim to know if the satoshi might start to have enough of a value that it would be better to continue to recognize further subdivisions of it by the time that the mining reward splits in half down to such an amount that more digits become relevant.  2048 is quite a ways off, but I could imagine sats having a decent amount of value by 2048, even though surely we cannot have a lot of confidence until maybe we start to get closer to such date, and maybe there would become a kind of sense of necessity to be able to recognize value beyond 8 digits, especially if the accuracy of the mining reward might seem to justify it..