The only places I can think where you can't long rest are the mind flayer colony, the nautiloid, and the nightsinger's astral void. I think everywhere else is good to go for long rest as long as you aren't in combat.
I thought of another one, Bhaal's temple you can't rest in. You have to go almost to the waypoint on the bridge outside it before you can rest again. Iron throne and the Foundry also.
BG3 has events where you can't sleep or they complete without you.
Waukeen's rest burning is the first one that comes to mind. If you stumble on it and then rest, Counselor Florrick will die. You have to complete it when you get to it. In a similar vein if you travel to the mountain pass before saving Halsin he will die in the goblin camp. I think that's because multiple days pass in the story when you go the mountain pass route instead of the underdark route.
We're pretty welcoming here. If they were star trek themed i'm sure they would be a hit. Hell you could use Hemmer and Geordi since they are differently abled.
