So we model shoes in rhino, flip all the normal in there and then when we bring it into keyshot we UV unwrap. These models are easily into the hundreds of faces at their worst. But it's not very complex geometry, so when UV unwrapping 9 times out of 10 the quick unwrap works really well.
The big slowdown comes from having to select each face manually, open the unwrap tool, Unwrap and apply, move to the next face, etc. etc.
If we could select all the faces we wanted to unwrap at once, usually we have 20 or so core faces that we'd want to fine control the unwrapping rotation but not have aren't complex enough we need to worry about seams and the like. To be able to mass select them, open them in the unwrap tool and work through them all in there would save so much time. I understand it won't unwrap well for all faces but that's easy to check by applying a UV checker material to all faces, then going in and tweaking the left overs manually like normal.
This is also the same for the flip normals, we do our best to sort all the normals in rhino before importing to keyshot but often if we've used the re-tesselate tool it will reflip all the normals on random faces, same request here, to be able to select all the flipped ones (I tend to use the back facing mask node to see the incorrect ones) and then click flip for all at once would save hours from our workflow.
Anyway I hope that made sense, would be a great feature to add for a future revision.
You can merge some parts if the have the same material applied and are connected neighbors. To merge them, just export these parts as an obj. Then re-import the obj file with grouped by material and toggle of "keep individual parts". Then check the normals and you can unwrap these merged areas in one go.
Hope that helps