Granted, while it does not make sense to discuss the physics extensions here since this is a track and not a car (obviously, duh), it does make sense to discuss track related CSP features for a project of this scale. Just looking at the weekly updates we get over patreon shows that this will still take a lot of time. Having features which mean "less work" are a good thing.
For the given example with the new grass shader, I can imagine having to place grass "manually" on such a huge area can be quite tiring and thus slow down other progress as well. So if one can simply set the surface to grass and have the grass appear automagically, one can heavily focus on other stuff.
I'd like him to use this feature. Also, people who don't use the shaders patch for performance reasons might not even be able to use this track in vanilla anyways due to the size of it.