Does it say the empty/dry camper can't be more than 1700...or the loaded (GVWR) camper? Perhaps they are accounting for 1000 lbs of:
Sometimes they don't trust you to really do the numbers, so they back things off for you. But the CG height difference sounds reasonable, too. Make an emergency lane change, and you could really unload 1 side and lose control.
thebrakeman ('70), DW ('71), DD ('99), DD ('01), DD ('05)
2004 Surveyor SV261T (UltraLite Bunkhouse Hybrid)
2006 Mercury Mountaineer V8 AWD Premier
Equal-i-zer WDH (10k), Prodigy Brake Controller