uv spline armatures

I'm not sure if anything like this exists in other apps already, and apologies if this is already possible with grease pencil, but it would be great if you could freehand draw a line over uv's and then manipulate the line to manipulate the uv's with the aid of proportional editing.

Sort of armatures for uv's....

Great for when you have a bent pipe for example that you want to straighten out.