When we work with UVs we have a lot of UV Maps, but we only have one seam channel for all that UVs. If the UVs have different island work with this type of asset is hard. A solution could be change the seams map depending of your UV selected.
I think that could be handled by edge groups.
We could imagine edge groups to store several UVseams sets for several UVmaps, several Sharp Edges sets for several Normal modifiers, several Bevel Edges sets for several Bevel modifiers, several Seams edges sets for several Subdivision modifiers or several Freestyle Edges sets for several Linesets.
But the workflow is a few different, but it’s true that it’s an option. But from a good workflow perspective, internally could any implementation, that user can change the seam when have one UVs selected or another is better way to handle this.