Maya 2020 UV Sets infuriating - need help : Maya (reddit.com)
sometimes you need to kill uv maps, you have to move the one you want to delete so it isn't at the top of the list - it can only be moved if you use the UV Toolkit mode - right at the bottom of the tabs there'll be a UV Sets rollout that lets you do so & delete the offending sets. VERY SHITTY.
