Interesting mention of roll center since the coupling between the trailer and TV and their roll centers have a large effect on the stability of the total system.
On my VW station wagon the IRS has a pretty low roll center and negative camber. It also has a rear anti-roll bar standard. With the stiffer, more highly damped rear end the trailer -TV combination works quite well and as to stability if you sharply displace the steering wheel the combination reacts and also damps out ant oscillation very quickly!
I am currently rebuilding the '86 Scamp
16 footer and changing the axle
for one that has some suspension travel left. I have chosen the Flexiride since I can change the ride height ans since I had to buy new wheels anyway (no 4 lug hubs with brakes
available) I went to 14" wheels and 205 75 14 tires
which are taller and therefore have (perhaps) more sidewall.
I am working to keep the CG low and the trailer balanced as I build to retain as much or the good handling as possible.
I would like to have shocks for this setup. but I don't think that the orbital system will fit. As a result I am looking into importing a set of the AL-KO octagon shocks and welding the necessary brackets to the trailing arms.
Since AL-KO is the originator of the rubber suspended torsion shock I assume that they know a little about whether or not they need additional damping!