-OBJ zero problems, export FBX to others softwares no problems so far, I don't really know about importing because mostof the time I do stuff in Blender. -in Blender no macros sorry, there was some addons, but I didn't really have a look into it. -splines are not good, but fortunately there is non-manifold workflow that…
Or use the data transfer modifier: put the faces that you want to transfer UVs for in a vertex group, add a data transfer modifier on the target mesh, put the source mesh in the Source Object field, check Face Corner Data, pick the algorithm you want (I like projected face interpolated myself, but you may be in a different…
Just using the operator on a selection is of course going to be different, because you are missing the information of the neighboring faces. You could experiment with duplicating the mesh object, adding a subdiv modifier to it, then subdivide your selection, then add a shrinkwrap modifier to the original mesh, with the…
If you use Shift+D to duplicate the object it will have all the modifiers and such on the new object, however you would need to go apply the modifiers from the settings panel. I assume the goal is to have a copy of the original, unapplied model for backup purposes before making additional changes to the new version with…
Unfortunately Blender doesn't have a modifier similar to Max's Smooth modifier. This is a really weird behaviour all right. Although not ideal, you could save the hard edges as a vertex group and recall them later when you need them. I really have no idea why it does this. No other DCC that uses opensubdiv does this.