The only maintenance items on my Gasser are lube points and general inspection. Oh and a fuel filter.
I'm 6'plus (about 6'2 now days peaked at 6'3) and over 300 pounds and with the rig sitting on the ground, Jacks up, can slide around under most of the motor home, can easily access ALL lubrication points.. Pick it up and drop it on jack stands (I have 4) and it is easier.. Some places I can even SIT UP and work on the rig...
As a Radio Operator I've run several coax runs half the length of the RV as well, all under the body and again no problems working there.