Have you've ever been to a desert planet or around a lot of gravel and sand? Then I'm sure you have experiences what I'm thinking about. The total collapse! It's frustrating making one small mining mistake and watching the whole structure of blocks around you and above you just collapse on top of you. I think the generation of the gravity affected blocks should have "support" blocks underneath them so it won't make for a total collapse and it will make more sense logically than blocks affected by gravity are floating on their own with no support. (until someone bumps one of them) But the support blocks should be somehow related to the gravity affected ones. (ie. fine sand supported by sand or sandstone, gravel supported by cobblestone) It should be at least 1 block deep (maybe more) of the support block directly under the bottom block of each column of the gravity affected blocks. That way the blocks affected by gravity aren't magically floating on their own and it will logically make sense.
