As of now, when choosing your terrain's quality, you will simultaneously alter wether you have grass or not, wether the terrain will be detailed in the distance, the amount of grass around you and wether the terrain will have those little bumps around it, all which are set by a simple "LOW" "MEDIUM" "HIGH" and "VERY HIGH" parameter.
Unfortunately, this does not allow for any customization, for example, I dislike having grass on my game, but were I to disable it, I would also have to make the terrain look really plain and under-detailed.
I would love to have the terrain options be broken down into different aspects, just like the Post-Processing option was.