UV Unwrap Pin strength

In UV Unwrap mode vertices can be pinned to not move them when doing another unwrap operation. Currently they either can be pinned or unpinned.

I'd propose being able to assign mid-values to pinning like a weightmap.

Example of why this can be needed: Imagine you have a planar projection of a cylinder from the viewport. Now you only want to pin a few vertices facing the camera and then unwrap the rest in order to project a decal or similar. When you do a new unwrap the unpinned vertices will get flattened but along the edge of the pinned verts there will be a visible stretch-seam.

Smoothing the pin strength before doing another unwrap could easily mitigate this problem then.

This example is mostly for deaaling with super high dense geometry like CAD or scan data, where it's not as easy to go in and manually smooth out or move individual vertices.