Just going to repeat what I've said in other threads...
I'm fairly certain that being able to rest whenever we want is by design.
A lot of plot elements are tied to the camp. That's why there's only one short rest, and combat's on the more difficult side. It's designed to encourage you to go to camp, which in turn moves these plot elements forward.
In the final game, we'll have even more companions, which means they'll want us to juggle our party around frequently. There'll be even more in-camp discussions during Act I before we decide who the final 3 will be.
