There are many reasons when I need to lock some UV points.
I need a quick and easy way to do it.
For example : I want to match some points from one UV island to another one, some of the points are ready for the matching operation but some other need a small move (progressive selection) for the operation to be correct. Having one island over the other one, it would be perfect to lock one island to not edit both but just match one on the other.
For now I have some workaround but, it woud be more quick to have this feature.
Cheers