I personally like to see companies sponsoring maintainers. We’re working to clarify that with the community is the terms have different value propositions & financial implications.
"Sponsoring" is fine, but for business processes you need a paper trail where something gets invoiced somewhere. It doesn't matter for tiny amounts, but your accountant will want something to hand to the IRS if there's ever an audit.
From what I understand, you're not 1:1 giving the money to some maintainer that's chosen but you'll distribute it according to code usage etc, so you won't be a payment provider, but it counts as revenue for you and you give the money to maintainers, right? Are you invoicing or do you go the github route?