It's nice to see the ever-increasing LYT object cap!
Just had a thought - now that we have concrete slabs, would it be hard to create a grass/gravel slab? I don't know how it works on your end but what I think you would just have to change the texture, lower the coefficient of friction even more (it's already lower compared to asphalt), add dust particles and there you go, we have a grass/gravel slab! Would be wonderful for rally stages.
Then again, it probably isn't as easy as I think but it's a thought.