safe T plus made a big difference. It makes the tires track straight. This fixes the steering issues. Think of it as fixing the Ford chassis and how it all works.
The Tiger Trak stabilizes the box on top of the chassis and reduces the sway of the box particularly when big rigs are next to you.
After that, you need to check your weight distribution of axles and toad weight. I would guess after all that, you should be in pretty good shape.
Sad we have to spend all that to make them driveable but it sounds like a lot of expense to buy a pusher and then do this all over again.
good luck.