But why its called UV Keep corners if it does not actually keep it? It should keep UV corners not mesh.
And this is not my wish, this is how other programs work with open subdivs.
I don’t know how, but they keep UV corners sharp…
Just test it on simple cube in other soft.
and that’s why we have this stretches
and other soft
Added:
another thing if its a plane like mesh
I can’t understand how it works, what should be sharp.
Maybe if mesh “closed” then unwrapped UV corners would be sharp, if mesh “opened” and some vertices have more then 2 edges, then this corners would be smooth, if vertex have only 2 edges then this corner would be sharp.