Ahhhh, well, that clarifies things more. :)
I have never owned a 30 plus feet TT so I can only offer what worked well for me on my 27 foot TT.
So I guess if I move up to a 32 to 34' trailer, I had best remember what you are going through with yours!
I would have thought that the frame would be sturdier on a bigger trailer, thus making it more stable, but perhaps not. I actually didn't think it could move in the middle with the corners supported, but my opinion on that one is conjecture, not experience!
Now I'm picturing it bending and twisting going down the highway - LOL!