One thing to remember is the simulator is for a Euro Trailer !
I disagree -- The simulator starts off with some tongue weight and one can move stuf around like a real trailer to affect the center of gravity and the tongue weight. One can make the tongue weight less than zero (like sticking a motorcycle on the back of an Egg) or get it close to zero or bring it up to Euro norms or bring it all the way up to North American norms.
Then one can accelerate up to various speeds and swerve to induce sway and see the results. One can be at Euro speeds or Calif speeds (55mph towing) or higher speeds.
One thing that might be different here is that we often use TVs with longer wheelbases, but for someone pulling with an Element or Outback or something like that, the model is quite valid (and a longer wheelbase, high-pressure LTs, etc. is only going to resist some sway).
Another thing MIGHT be the typical length of NA trailers, esp eggs, from ball to axle, compared to Euro trailers, but I doubt that would be too far off.
A more sophisticated version of the simulator would allow wheelbase, overhang, ball to axle and axle to rear bumper variables to be inserted.
All that said, however, it's a very good point to mention that getting higher and safer tongue weights on some vehicles exceeds the manf's recommend limits for TW -- That means that the TV and trailer are indeed unsuited for each other (unless a Weight Distributing Hitch can be applied to distribute the TW to the front axle and trailer axle).