Never run in hosted sessions, so not quite sure how setup restrictions work. Do they have so the host can create a custom setup and require that all cars us it? Is this what we mean by "fixed setup"?
The only problem I see with running fixed setup is catering to both the exerienced and less-experienced drivers. That being said, I am leaning more towards fixed setup than open setup. It's comforting to know I'm behind for no other reason than my driving.
I really don't know much about restricing setups in hosted sessions or tuning itself, so I'll leave this discussion to the more qualified participants.
Copy that on waiting to further discuss the schedule.