I have two suggestions that I think would take the wonderful Masking inside of Topaz Studio over the top. One would be to add a density slider in the Mask adjustment section and the other would be a View the Mask button that would turn the image into a Mask so you could inspect it more closely.
I am not sure if this is what you are looking for but if you press the adjust option in masking, you are given some options that include density.
Love the idea of being able to better see the mask.
I missed that. Thanks.