I was legal with a 12K total equipment trailer, 1500 lbs of hitch wt with my 8 lug single wheel trucks. Thats going back to my 88, 96 and 2000 trucks. Not to mention my 05 DW 3500, and my 82 IHC class 6.
WD systems have no requirement in laws, at least here where I am in Wa st. Same with sway control. Altho having a trailer that goes IIRC 12 if not 18" side to side will net you a moving violation, along with getting red tagged so You can not move the rig until you show the trailer with not go sideways uncontrolled. If that takes a sway bar, great. If you can do it shifting weight etc with in the trailer, great. If not, you can find a low boy or tilt deck to get the trailer off the road!
marty
92 Navistar dump truck, 7.3L 7 sp, 4.33 gears with a Detroit no spin
2014 Chevy 1500 Dual cab 4x4
92 Red-e-haul 12K equipment trailer