I wanted to add that Daz is not only some “raw framework” but more like a very advanced character creator for gamedev, where the characters need just some small corrections during the export process (through blender).
As for the joint corrective morphs / muscle flexions: There are around 80 of them and the remaining ones have more to do with face expressions.
Everything works fine and you can even paste your old project files into UE5 and it seems to work flawlessly most of the time, but the biggest problem is the lack of a Dual Quaternion version for UE5 and the discussion in the corresponding thread seems to be dead.
Automatic merging of source code is not possible, because there have been too many changes in it…