I have hit the whole roof with 400 grit, half the roof with 1000, and then a quarter of the roof got an extremely brief polish to see if 1000 will be enough.
spoiler alert: it won’t be. The process will have to be 400 > 1000 > polishing mud > polish > wax
so... It’s still the worst panel (that can be saved) and I shall proceed with restoring it as practice for the sides, even though the roof will eventually be wrapped in vinyl.
the challenge will be to continue to bring it all to one shade of red, the white in the roof is DEEEP. and adding an extra step between the 1000 grit and the polisher, using an abbrasive mud that is something akin to a ~3-4000 grit