My 2014 35ROK has a 13,500 btu a/c in bedroom and 15,000 btu in den.
They are run by the same thermostat at the stair wall beside the bath.
Controlled by a ZONE button.
Keep in mind, if u have the two units, they must be on 50amp outlet to function at same time.
If u only have the one unit in den, then u must keep the quick cool slide closed to direct air to front of trailer.
Other than that, I am not aware of anything else that would block air from being transported to the bedroom, but I do suspect it would be a very lite flow of air from back of trailer to the time it reaches the front since the unit is almost 42 feet.