Lock initial sculpt normal, but keep going with position (TrimSmoothBorder)

To me, this is the biggest feature that's missing from the sculpt mode. I'm talking about the TrimSmoothBorder brush from zbrush. It's crazy good for making rocks and chipping away edges.

Right now blender has the scrape-brush which is okay, but the normal updates with the stroke. You can click a checkbox that says "initial normal" which indeed locks the normal, but it also locks the position (bad naming?). So locking the normal while still having it so that the brush follows your stroke is impossible.

I know that there are plans for making a node-based brush editing system, but honestly, this is so small thing I think it should be implemented immediately

Edit: thank you Pablo Dobarro for saving us all once again!