You can't ignore it but you can just apply default automatic UVs to your collision mesh in the first place, so that it can be imported in SP. Then you can hide the corresponding texture set and work on your asset the way you would normally.
Yes, it's a workaround but since there is a collision mesh for each convex hull it can get annoying quickly, you have to unwrap each collision mesh in a script to have Painter load them at all, you end up with 10-20 texture sets that don't do anything, you need to disable these texture sets in the list when working on your asset, you need to disable them when exporting and so on.
Anyway this is a feature request for a smoother system that just flat out doesn't load these extra meshes that you don't want to see in Painter but still would like in the .fbx so you can import it with everything in game engines.