Travelling, we use the dash ac set on max cool mode to start out then may turn on the overhead front windshield defrost fans to low.
Our next step is to start the genie, turn the front roof air to on, fan set to manual high speed.(keeps air recirculating through the coach better than letting the ac kick on and off in auto mode)
If really hot, mid to low 90's, we turn on the rear roof ac in the same manner as the front roof ac.
When the outside temps are in the 90's, we frequently turn the fan of one roof ac on manual high and leave the other on auto mode which does help even out the inside temps.