Whilst I've never tried taking them off a rib tube I do take a fair number off vans, cars & caravans during body repairs - so that's off plastic, grp, steel & aluminium which in the case of the first two may or may not be painted.
Any sticky residue comes off with brake cleaner - I've never had that attack paintwork - but 'tar and glue remover' would do the same job.
My preferred method is a hot air paint stripper to heat them up & they then just peel off. I have my free hand next to the area I'm heating to avoid getting things too hot as i don't want to damage the paint away from the area of repair. You don't need to get the surface too hot, just keep trying to lift an edge until it peels.
Trade customer of mine uses boiling water from a kettle to achieve the same result.