The Upol tech sheets say nothing about painiting over it except with another coat after 60m flash. They also say you can touch up later with no problem. I can call the UK office to ask. I sent Upol an email and will let you all know.
I suspect if I scuffed it (versus sanding out the course texture), it would stick but we'll have to wait and see... Maybe I'll test it on the top side of the floor pans that I have applied Upol as well. Afterall, that will be covered with carpet
Take care brothers......