agreed, payroll is hard - we actually mean only the payment part of payroll right now. we'll experiment on ourselves first by paying salaries in fiat+crypto to get a better idea of all the implications.
paying vendors is simpler indeed, and it's even better with crypto because you pay low fees (and not based on the amount you're sending)
we're totally aligned with what you're saying about the "secret sauce" - we actually released a feature called "direct transfers" that aims at doing that (except that it's not with a card atm) https://medium.com/multis/introducing-direct-transfers-a-new...
we need to go deeper in this "corporate bureaucry friendliness" though and have more levels (right now only owners/guests)
cool to see that you get what we're trying to do :)