FWIW, I would prefer that these different funding sources remain separate. I think it would create confusion, since the business models do not cleanly align. Tidelift gives maintainers a way of getting compensated in exchange for doing what they already do (or would, should, or want to do, given the resources), and the companies that pay Tidelift are getting longer-term assurances on various aspects of a project are addressed piecemeal by other platforms and one-off approaches. This doesn’t match up with bounties, for example. Tidelift’s model is really direct, and it’s clear how economic value is created for all parties, and it’s also clear how Lifters can scale out while only minimally increasing in maintenance burden.
IMHO, other platforms would get more benefit from Tidelift than Tidelift would get in return.
This is just my 2c