Different corner smoothing for copper zone and solder mask

Dear all

I noticed that fillet corner smoothing is done in different ways for internal corners on copper zone and on solder mask. As you can see from the picture attached, internal corner for copper zone is not smoothed with default set of parameters, which is not the case for solder mask.

By checking the box " Board Setup… → Design Rules → Constraints → [x] Allow fillets outside zone outline" I am able to make smoothing for internal corner on copper zone, but I wonder where is check box which allows to do the opposite for solder mask

P.S. I am using Kicad 8.0.1, Linux build