I would agree it seems like 100 lbs would be pretty light in that as I recall the original hitch had a fairly long arm and when you look at the images of the DRV units the axles are well forward so the Avg axle to pin distance could change a considerable amount it would seem with a straight pin box.
It seems that we are talking two sets of dynamics on the DRV units ........
The "Z" axis (vertical) seems to tend to become "excited" when the light pin weights are too light to become dampened by the tractor suspension interface to the air suspension hitch and without the minimum weight on the pin you have too light loads to allow the two suspension systems to attain design minimum dampening values.
The second dynamic seems less serious to most of the HDT's is lateral excitation with a roll coupling component......I do recall that at least one forum member seemed to have had a tail-wag adventure but for the most part I would assume that most HDT's have plenty of dampening to keep the DRV fairly well in the lanes.......until the truck needs to turn quickly and then thing could become excited......
From a weigh & balance stand point it would be nice to obtain detailed measurements of the load-centers (fresh water, grey, black, battery banks, cargo bays etc) and with these details and the axle to pin distances it would seem that the pin weights could be adjusted AND perhaps the weight distribution could be tuned to improve the tow qualities of the DRV units when towed by a HDT.
The straight pin box is likely a good start and then with KNOWN load adjustments the units could likely be improved nicely.
Drive on.......(adjust the ride and enjoy the ride)