[throwaway82652]

> If upstream denies or ignores your pull requests, you're dead in the water

No, this is very wrong. You can maintain a fork. You can do that while maintaining positive relations with them to see if eventually they do decide to take the PR.

Of course nobody wants to do that because it's a lot of work. So what's really happening here is you're trying to play hot potato with a feature that nobody wants to maintain, not even you. I sympathize, I also have patches sitting around in various projects that went nowhere. There just isn't enough time in the day for unpaid volunteers to look at every patch.