I hear you: there’s not a single filament that does everything. I wish there were.
Have you considered a 2K polyurethane coating like a SprayMax to get the UV resistance you’re looking for? Or possibly some kind of fire resistant ASA enclosure to go around your enclosure that you need to be UV-resistant? You could theoretically print the shell over your existing enclosure, and maybe with some clever interlocking ensure they hold together. Bambuslicer supports it. I proved it out here: