Using a passphrase (25th “word”) is comparable. You can use this technique along with multisig. It suffers from the same single-point-of-failure as shares, but the passphrase you store only in your head.
In this way, a passphrase is additive to your multisig security posture, compared to shares which weaken it.
I'm afraid that's too complex for my wife. Seed XOR is also too complex for her, but not me. I like Seed XOR because it does not add complexity for my wife because I can have the seed(for her) and split the seed(for me, the bitcoin autist🤓).
I am also shell shocked from the pandemic. I used to keep my key in a safe deposit box only, but 5 years ago, I couldn't access my Trezor for 3 months and when I finally did, I learned my passphrase had a typo. I figured it out after a couple weeks, but I don't like using passphrases with multisig because of this.
By the way, I'm not arguing with you to be a jerk, but to bounce off ideas and improve my own security.
It’s OK. There are two ways to lose your coins: you lose access to the keys, someone else gains access to the keys. Defending against either one in isolation is easy. Security is about balancing both.
Seed XOR is equivalent to a 2-of-2 multisig. IMO, genuine 2-of-2 multisig is superior, for the reason previously mentioned: that seed material can be kept separate at all times.
The tradeoff is that witness data on chain is marginally larger, making spends more expensive. Spends also reveal the fact that it was 2-of-2, so slightly less private (unless using Taproot, which would be the same as single sig privacy wise).
