>Except with Android I can't submit those patches back to the main project, so I have to maintain a separate fork myself

Open Source doesn't give you the right to get patches accepted upstream, it gives you the right to have your own fork. If your fork is worth it's steam, other people will like it and join you, otherwise it will die off when you lose interest just as it should.

>This isn't sustainable for more than a few patches

This is true, but sounds like it could be countered by starting a fork as a community project so that anyone with just a few patches can submit them to your fork. This would also likely increase interest in your fork and may help find someone willing to take over admin rolls for you, since that seems to be your goal in all this.

Look, if all you want it to be able to publish a few patches and upstream won't accept them, then include said patches in a blog post. That way they're in the wild, and you don't have to maintain a repository. Just a thought in passing.

So start such a community fork. That it hasn't happened yet seems to indicate that manufacturers don't even want it.

Also there might be community mods, like Cyanogen (haven't really looked into them).