from various information sources, by summary concludes the current seed phrase storage as best:
2 of 3 multisig.
-snip-
These 24 words are then engraved onto 3 stainless steel hexkeys, so when 2 of these hex keys are brought together, the 24 words are revealed.
Then the user needs to enter the passphrase to fully recover the wallet.
I have a feeling that you're mixing things up since MultiSig isn't a "
seed phrase storage" scheme but a bitcoin locking script that can only be spent by providing the required number of signatures.
"
MultiSig" standands for "
Multiple Signatures".
By the given example, it looks like you're talking about "
SLIP39" (
github.com/satoshilabs/slips/blob/master/slip-0039.md).
Browser example (
for testing, don't use in real wallets):
iancoleman.io/shamir39/My understanding is a seed phrase will have 24 words.
For 2-of-3 MultiSig Setup, you'll be backing-up three separate seed phrases.
That "
2-of-3" signifies: the 'number of required signatures to sign transactions' - of - 'total number of cosigners'.
Since it's "
of-3", you'll be creating three cosigners wallets which contain their own seed phrase.
12 words per cosigner is safe, but if you can backup 24 words in a single steel hexkeys and the wallet can generate 24 words, then go for it.
Read the links in the reply above for more information about MultiSig wallet setup.