But, a multisig vault can have some advantages compared to the singlesig wallet
I agree with most that you write, I just want to add some video of Andreas about multi-signature:
MultiSig is NOT the best option for most people to store their bitcoin [June 2023]Also Multisignature transactions need more space and it waste more fees each time that you want to create a new transaction.
As experiment it is OK and its up to each person to use it or not, but i think that a single 12 word seed and 24 words bip39 seed have enough security always that you don't leak or mesh up your seed