[Feature request] disabling sand/gravel falling

[megaloloful]

Hey VikeStep I have a small feature request for you that will propably help me to fix a really big problem I have with a modpack I'm making. I'm not gonna say much about the pack but I'll tell you that you have to go to new generated ages a lot and falling gravel is a big lag problem. The first thing that came into my mind was disabling gravel falling. That's why I created this feature request.
If you have a better idea than this one I would be happy to hear it.