What I did with my Workhorse was both a stabilizer (Today I'd likely go with the Safe-T-Steer with the optional remote adjuster. back then only Blue Ox had a remote adjuster.
And a Trac Bar
What's a Trac Bar (Also known as pan-hard bar)
As you know the springs allow the axle to move up/down relative to the body (or the other way around) But LEAF springs (Common on Motor homes) also allow some side to side movement.. So if the front moves say to the right as the rear to the left... You think you are headed into the ditch and thus adjust.. then they swap and you think you are headed into the oncoming lane (2-lane) or the other lane (4-or more lane) and you adjust, then they swap and you .. Well that's where we started .. So you are actually weaving down the road. but not the way you think.
The Trac Bar LOCKS the body, side to side, over the axle so this simply does NOT happen... two of them (Front and rear) stop "Wag" 100 Percent one is often enough (Was for me)
how much difference
Trip Detroit to Las Vegas in 2006 (jan) was a relief to park RV and drive towed
2nd trip. Nov same year.. That towed (Same towed) Was much harder to drive when I got there. Way way harder (Same towed exactly I'd gotten used to the RV)