Great idea, But it might look a bit strange and unnatural from small drops, (Earth passive still triggers from small drops) so you might wan't to add a depth variable which determines the size of the crater relative to distance fell. If its a very small drop, keeping the sand particles would seem more natural, Although vary them by block landed on possibly? So if you land on stone, You get gravel, If you land on grass you get dirt, This might look better than just sand for everything.
tl;dr
-Crater size depends on the distance you fall from.
-Change generic sand into more relevant blocks depending on the block you land on.