What features are missing from the UV editor, either that you thought of yourself, or that you have seen in other software?
It can be anything, a shortcut to a feature that’s already there, a whole new function, an addition or edit to the UI. It feels like it’s missing stuff, but what?
The thing I miss most? Vertex Relax. I use it a lot when modeling (it’s in the included add-on Edit Mesh Tools), but then I go into the UV editor, it’d be the perfect tool for smoothing out a few spots, but it’s not there.
I wish the UV pack operator supported more complex packing of shapes. Currently it seems to use the bounding box and supports only basic rotation, but it can’t put UVs for one section of a mesh inside the hole of a donut shape for example, an an L shaped section will waste a lot of space because of this limitation. There are some addons that do a good job of more complex packing, but it would be nice to have in Blender itself. The default padding amount is also too small, so I always have to change it, which is a little annoying.
The ability to keep UVs symmetrical, better handling/prevention of overlapping and UV stretching, and it’s frustrating as hell when you try to adjust the vertices in the UVs and blender rips them instead. Loop slide like we have in edit mode would be nice too. Never mind the things that I’m only not putting on the list because I have addons that make UVing in Blender less terrible.
Really the only benefit to doing UVs in Blender is that it saves you time on exporting and re-importing. Blender is an absolute nightmare if you want good character UVs. Never doing that again.