My use case is as follows: I would like to apply dirtmaps to my road using the default UV set 0. Along the road are custom road marks which are split out of the road (That way I can define the spacing size, etc on my own). I would like to have the road + the road marks to have a consistent dirt look via dirt maps.
Is it possible to copy the current layout of UV set 0 to any of the other UV sets, such that I can manipulate UV set 0 at a later stage and the UVs for the dirtmap are untouched?
No, sorry, it is currently not possible to copy UV sets from one set to another. More details are in this other post.
I'm aware that I can delete a UV set and it will default to UV set 0. However, changing the UVs afterwards also changes the UVs for the dirtmap. So the simplest way to handle this would be to copy the current state of the UV set 0 to different UV sets. Is this feature in planning? Has this been discussed internally? I suppose the implementation effort for this feature would be quite moderate...