A warning at the start that I am fairly new to this whole thing and will likely get at least something wrong throughout this explanation/question.
I'm currently trying to configure the settings in such a way that a Traitor subrole (like Infected or Defective) is entirely mutually exclusive with both other Traitor subroles, but also so that they are the only Traitor that appears that round (so if there is an Infected, there are no other Traitors).

I'm also unsure if my role layering menu is incomplete or in some way broken, as it shows Detective, but lacks Innocent, Traitor, and most importantly Defective.