If I select light, medium or heavy supports and place one of each then I see the difference in contact diameter. However, if I try to decrease the size of contact diameter to something less than deftault value then the diameter doesn't change. Doesn't matter if light, medium or heavy support is selected. It works if sphere is selected as tip but when using none as tip type then contact diameter doesn't scale. 

Also, I had a suggestion for future version. Allow user to modify supports like they do now but have a temp area on screen that shows the new values for that support so user can set that same support and save it. Also, it would be nice if there were keyboard modifiers that allowed the user to scale the contact diamter, contact depth, etc while physically editing the support. Also here would be nice to display what the values are so user can save them for a custom support type/size.