Hello :)
To start, I'd like to clarify if there actually is a problem which is in need of a solution.
From what I've seen so far I've got the overwhelming impression the current donation systems work. I also think we have more than enough instances / capacity in the network.
I'm a bit worried about introducing a payment system which could be gamed for profit, and I'm worried about introducing a capitalist mindset into an ecosystem, which (as far as I can tell) works fine without.
But all that hinges on the question if there is a problem which needs a solution. I'm not claiming that's not the case, I just don't see it yet.