I'm in agreement with controlling both sides individually. If you had a load of fire wood and were traveling along an incline, if you had both bags plumbed together, the lower bag would have all the weight and the upper bag would be at its upper limit. Therefore, I'd be pissed because I'd have to lick that darn calf over again!!
control them individually and use what is available that will provide much better flow than what the big rigs have. These smaller trucks and the loads they haul react quicker to input than a big rig. Therefore, you need quicker inflation/deflation.
Just my