If you want to support GIMP on Patreon, here are direct links for the key developers:
there is clearly market for something more efficient...
Such a service could also have a "release funds now" option for emergencies where you'd accept paying hiked-up fees.
Basically there's no way to determine the card has 3 months of $1 on it when you want to make the charge and if you make it earlier you pay the fees.
I was just thinking about the intermediary->payee bit. I forgot the payer->intermediary bit, and that this is a credit card charge too.
Now I realize I mentally modeled the whole problem incorrectly. Thanks for pointing that out.