I have been looking at this problem as I have started to examine whether UE4 will save me tonnes of money in renderfarm fees for animations and movies of Skup models (for my RPG games).
I have been using PlayUp, and through that I have discovered that to get better (even perfect) UV maps you need to use a non-solid material, then ‘paint’ your model in Skup using the procedural technique – that’s right every single face needs filled by itself. Then you use the PlayUp editor to calculate meshes. This seems to get a reasonable result.
I suspect that there will be other tools to generate the UVs from and in Skup too. Say, if you wanted to export to EON’s Vue. If you are doing 3rd party rendering I heartily recommend that you sort the UVs before importing into any 3rd party, unless you like moire conflict and Z fighting.
If Skup is the pantheon of the Gods, it’s UV mapping system is the limping diety, Haphaestus.
I’ll let you know how I get on in the end with PlayUp.