Grease Pencil: An accurate Cutter tool

Right now, the cutter tool doesn't terminate lines in exactly the right place. Often a 'bump' is visible where the line has been cut.

It'd make things a lot easier if the cutter tool added a new point exactly on the intersection with the second line and deleted all points up to that new point.

(I initially reported this as a bug. It was classified as a known issue/limitation developer.blender.org/T78786 so I thought i ought to submit it here as a proposed improvement too)