mints are completely trusted, I don't see why they couldn't do anything they want. it's not like a multisig bitcoin transaction or something. there are no guarantees until its real sats in a lightning channel. I'm talking about accepting payments from random mints. it's not real until you do a swap (aka lightning).

ecash from a vendor-accepting-payments perspective is a nightmare, and you need to use lightning to verify the payment anyway.

if the solution is forcing the user to swap to your preferred mint then you are still relying on the user to use lightning to do the swap, which run into the "bad ux" that you are claiming to solve.