I've had only one gang bang experience and it was pretty much a disaster. lol Short version: ALL of the guys had spent time with her and I was the last one left on the bed. It was the two of us and the other guys started chanting my name to encourage me to play! Talk about the perfect way to "kill the wood". lol After that, I spent some "one-on-one" time with her and had no performance issues at all.
Anyway, I'm responding to your message because of your point about setting boundaries. I've watched a few "Hotwife Tour" videos where it's pretty much an orgy with a handful of well known hot wives are surrounded by hot studs and husbands.

During a couple of those videos, before the real action begins, the hot wives introduced themselves and stated what their boundaries were. "Hi, I'm {fill-in-the-name} and I love doggy style and I love being fucked hard. Cumming in my mouth is ok, but I won't swallow". And so on. So, maybe something along those lines could work where you talk with the guys, once they've arrived, and let them know things you're open to and not open to. Then, once the fun begins, you can forget about that stuff and enjoy the rapture.
I remember the late Faye Desiree used to really enjoy these gang bang-like parties she would have, where she could relax and be worshiped and ravished instead of focusing on pleasing her client, all the time.
I hope you're gang bang goes well!!!