Tried everything, is there anyway to “erase” stuff at all in Quick Sketch or are we just stuck with CTRL+Z?
Select the PenSoft brush and paint over. Use the ‘v’ key to switch between dark/light colors.
You are essentially painting/sculpting on a geometrical image plane, so it uses the same functionality as sculpting on any geometry. In other owrds, paintover, or undo.
If you want a more advanced and traditional image painting process, use the PaintStop plugin. Quick sketch is literally that…just a sort of quick and dirty doodle, like you might make on a ****tail napkin to get an idea down.