Glad you got it. The HVAC system is probably one of the bigger frustrations of these trailers. High and low are (as you found out) worthless. Auto works as it should.
On ours, the heater vent in the bathroom blows extremely well, the 2 in the living area are ok and the bedroom one is useless (I'm beginning to think the duct is crushed somewhere in the underbelly). However, I do think the AC works well.
This year, I put a small space heater (1500w) in the middle of the floor and that has helped even the temperature out greatly in the trailer.
2017 Forest River Surveyor 247BHDS...
...Tugged by a 2016 F250 XLT FX4 SuperCrew, Shortbed 6.2L, 4wd, 3.73...
...Joined with a Husky Centerline TS 800-1200lbs WDH