I have one object that I can't seem to merge/join with others or else the material/texture coordinates screw up. Tested in 2.79 and 2.81 with identical results. Apart from having to have UVmaps with unique names assigned to each of these - what else is there to look out for?
Yeah thats one of blender's short falls... the tweaking can only be done right after you create the mesh anything else and the opportunity to change its edge count or what not is lost after you do something else. It has been brought up though and I hope we can get a history stack in sometime soon.