Identical Overlapped UVs automerge

I'm overlapping UVs for a game asset to save on UV Space. I noticed, and it's somewhat inconsistent, but identical UVs tend to merge (without a way to disable it). The problem is that I need to move them to the next tile to avoid artifacts when baking.

The only workaround is to manually select the seam region and move it away with UV sync turned off.

This issue can be replicated by vertex snapping identical islands, but it also affects addons, as I'm using UVpackmaster 3 to automate stacking.

It would be nice if the islands were unique regardless of similarity, and if this could be a turn-on/off feature.