surely someone here has done this??

no, I haven't however, my grandson did paint mine. I would very, very carefully, sweep with a broom that is covered with a terry cloth towel - you want to get any dust, dirt, etc off first. I would then paint with KILZ or any competitor. Only then would I paint with regular paint keeping in mind I would ONLY purchase a 'name' brand, Sherwin Williams, Valspar, etc.

We painted our ceilings and they look like that. I am assuming it's the same thing. Anyways, we used ceiling paint from Lowes. Not sure of the brand we got the cheapest they had. lol No issues. Took two coats (I think). ETA: It's a 1970's single wide. So I am pretty sure it's the same exact ceiling.

Depends on what is on the ceiling. Dirt, grease spots etc. Clean it well use primer and paint resistant to mold if you have plastic spacers on rtge ceiling you will need a paint that works on plastic

I just painted mine with the Valspar ceiling paint that changes from purple to white as it dries. No problems and mine are popcorn textured.