Looks like a lot of work, basically it's the unsupported bsp pieces on all the different physical platforms, on Ubuntu.
This is a very thankless task if the board vendors (who will have access to Rockchip support) won't help either.
When there are a lot of different platforms, it's very easy to get your energy drained simply by an endless parade of small things, without getting to the point of completely solving anything. And there is no payoff since the vendors and rockchip lock up any profit.
Surprised there wasn't more interest in this here.
Jeff's video on this:
https://youtu.be/4aaF2HgTVe8?si=TAVC2qT3vqiqzpBk