That was my subconscious. 4 is the maximum, but I'd actually steer more towards 1 or 2 types when possible. If the diagram is very complex and needs more types,

That was my subconscious. 4 is the maximum, but I'd actually steer more towards 1 or 2 types when possible. If the diagram is very complex and needs more types, I'd try to split it into several slides. I saw the slide and the "visual complexity elimination subroutine" kicked in. I'll try to fix that in a future version.