If I have understood it correctly. Once you have established a SEPA account for example a Danish SEPA account. When users we want to shop with a Spain`s SEPA account. Then you need to create a new account at SEPA and make it into Spanish?. It is stupid if it is like that?
It should only be such that you only create a account that is connected to the bank or something like that. Why not let users pay with a visa card, Bisq give the user the money from the pucked and Bisq take the money from user the other day. That way users can buy and sell faster.
And Bisq, for example can take 0.07% in fee or just 1€ to cover the expenses.