but don’t lose it or you are fucked.
It certainly sounds like a broken record: if you use one or more mnemonic passphrases, make sure to very carefully and redundantly document them! Because if you loose or can't reproduce a mnemonic passphrase, you instantly loose access to your coins, which you expressed more casually.
It may sound obvious, but some people screw up the basic documentation. Human brains will inevitably forget complex mnemonic passphrases, so proper documentation is mandatory.
also the trezor has its seed my trezor 5 uses 20 words
IIRC, I don't use modern Trezors yet, it's Trezor's SLIP-39 new standard recovery word backup which encodes additional metadata and uses Shamir Secret Sharing (embedded entropy is 128 bits equivalalent to standard 12-word BIP-39 backup).
I hope other hardware wallet companies didn't fuck up their code paths for entropy generation and properly use embedded TRNGs in contrast to Coinkite's Coldcard mess. At least some companies did code audits, but those don't guarantee you find every flaw in your code base.
yeah I am going to make 10 passphrases using a set of punches
the punches are
A to z thus 26
0 to 8 thus 9
and * thus 1
that is a set of 36 different punches.
shake them in a box pull 1 punch
replace it in the box pull 1 punch
so 1/36 x 1/36 until I do a large passphrase
2 pulls is 1296 combos
3 pulls is 46656 combos
4 pulls is 1679616 combos
5 pulls is. 60466176 combos
6 pulls is 2176782336 combos
7 pulls is 78364164096 combos
8 pulls is 2,821,109,907,456 combos
now I can fit 8 punch marks on a stainless steel washer.
and 1 washer means 2.82 trillion which only slows the attacker some what
but 2 washers mean 2.82 trillion squared better
and 3 washers means 2.82 trillion cubed even better
now if you have a 20 word seed and 3 washer 24 symbol passphrase you have a decent stoppage of a hack.