According to Tails official documentation[1], and considering the scenario mentioned by you, you are free to choose if you want to keep your Persistent Storage or if you want to clone the other device Persistent Storage. See please section "4/4 Upgrade your Tails by cloning" of the mentioned URL and you'll see the available options during the upgrade stage:

1. Everything is done within the device. Your seed phrase and private keys never leave it, not without you authorizing it from the device anyway. Now obviously, not all hardware wallets are equal, and this is why it's a good idea to go with open-source ones.
2. Depends what you want. A multi-coin wallet? a bitcoin-only?

You will be much better off with an open-source, open hardware, airgapped hardware wallet.
I can't believe that nobody is really criticizing this 'old computer' idea. Your 15-16 year old PC will most likely run outdated OS and / or packages, which are much more likely to be exploited than bugs in the CPU.

No wallet or OS is completely safe. Any wallet and pc can be compromised. Regarding the hardware backdoors, I totally believe they exist (we're livin g in the age of surveillance) but the question is if the manufacturers want your Bitcoin or something else?

If your hardware, for example, CPU is backdoored, then you can do nothing other than to change it with another hardware. By the way, like you, I'm afraid there is a high chance that modern expensive PCs or Laptops may be backdoored, that's why I prefer to use old device for that purpose.
Along with the air-gapped device, you need to take care of the special environment where you plan to store that computer. You need to block radio waves in that area.
Also, everything depends on where you live. If you live in a country and in a neighborhood where people are in their 40s and don't know how to use tech and kids/teens around you are having fun and rarely know a thing about IT and coding and they only use pc for gaming or gambling, then you can feel more secure.

You really wan to go down this rabbit hole, checkout just what Intel's Management Engine (ME) and AMD's version of it do https://en.wikipedia.org/wiki/Intel_Management_Engine
It's access to system functions is so pervasive that the NSA required an 'off switch' to disable most of its functions for secure hardware... https://web.archive.org/web/20201201175708/http://blog.ptsecurity.com/2017/08/disabling-intel-me.html?m=1

it can be safe then and only then when :
1. No one has access to your hardware
2. hardware is offline.


if it is online...you know..


Online - I mean Blouetooth, WIFI, LAN, 5G, WIDI, and direct connect.

Few years ago I have read about GPS connection- it can be virused too , and their had "connect". at the time it was weird for me. but now, no. Everything is signal, code.

If your transaction is rebroadcast it would still be stuck on the mempool because the current network is pretty congested.

Would you mind telling us where the BTC came from? If it was from the exchange the only thing that you can do is to wait for the fee rate to drop on the mempool.
Or your final hope is to do CPFP would you mind to try to make a transaction while its currently unconfirmed go to send page and then make a transaction to send it to your receiving address this time make sure to change the fee to prioritized.

Thats quite a long time already. I hope you don't try to rebroadcast your transaction now since there's no use in doing so. Let it drop off the network automatically by next week.

You can see the fee rate of your tx on mempool. Just go to "mempool.space/tx/<your tx id>" and you will get a fee rate column under your transaction. You can also check the average fee rate (in sat/vB) on top of the mempool to get an idea on how much fee is required to get your tx confirmed faster next time

Just as expected, the coins just disappeared from your wallet but it can't be removed from the explorer just by yourself. Btw, can you tell for how long your tx is pending ? An unconfirmed transaction can remain on the mempool for 14days before getting dropped back (meaning sent back to the original sender's wallet). And how much fee size in sats per vByte did you pay? That can give us an idea to help you with the rough estimate.

Now, talking about bitcoin transaction accelerator, there are free tools and paid one. I know viabtc still have free accelerator you can check it here^[1] but take note that the transaction fee should be >0.0001 btc. But for your case it's probably below because you will not go here if its the case. The paid one i knew is pushtx.btc.com but they already stop their services way back 2021.
On the other hand, if RBF is not available, your only option is to wait either it drop by the network so the balance will appear again to your wallet OR it got a confirmation after days worst if weeks.

[1] https://www.viabtc.com/tools/txaccelerator/

I do not advice anyone to use that wallet because it does not have an easy way to backup your seed phrase. You can backup the wallet file, I guess, but the seed phrase backup is never easy.

I will advice you to use Bluewallet or Electrum on your Android. They both support RBF too.

I am not Bitcoin Android wallet user and I do not know if this would work, if it does not work, wait for the people that are using it, to post. On the wallet, you will see the transaction in the transaction history or so, click on it and see if you are able to see where you can pump or increase the fee.

If you are able to get your seed phrase, import it on Electrum to pump the fee. Download Electrum from the official site: https://electrum.org/#home

I guess this the famous bitcoin wallet by schildbach^[1] and this should be moved to that board.

And as for i know, the RBF should work only have the balance on your wallet.

[1] https://github.com/bitcoin-wallet/bitcoin-wallet