Why not change the relationship? Find a contributor - on the team or not - working in that area and ask about their rates and what it would take to hire them.

Why not change the relationship? Find a contributor - on the team or not - working in that area and ask about their rates and what it would take to hire them. Some will not be interested but some will be. At that point, it's a patch but created by someone active in the project. The worst case is that you can apply it yourself. Not great but immediate problem solved. Long term, when you go back to the core team, you have a patch that has been tested and used, built by someone in their community, and you're not making a demand but helping address a gap (real or use case specific). (I've worked on and managed OSS projects for 10+ years and this works pretty consistently. It requires a little more work up front but you end up with a better relationship with the maintainers and a growing network of people who you can contact for specific issues.)