Trickier to set trajectories, but performance-wise, it works much better than I expected! And we can even get particles colliding with track at almost no price. Here are some more videos:
One problem so far is that online, for remote cars, whole thing will be quite simplified, as there are no car-track collision events being sent (I still have a few bits left to squeeze at least a couple of flags regarding collision in though). Replays already work fine. 😃