ZBrushCentral

Mask with topological turned on doesn't quite work

I’m trying to mask out a collar on a jacket with MaskPen with topological automasking and a low range and it still spills on the jacket bellow. Is it a user error?

Nobody knows why this doesn’ work? It would help me greatly to separate overlapping thin shapes like shirt sides at the buttons and similar. It works as expected with brushes that work on geometry directly like move and standard and others. I just cant get it to work with masking.

To answer my own question, topological + BACKFACE masking works fine for stopping masking spill on underlying surface with the pen tool. Other masking types + automask don’t seem to work.