Makes the player collide with belts. Alternatively, with a mod setting and a new game, makes it so the player can ONLY walk on belts (and gates).
Small changes concerning balance, gameplay, or graphics.
Transportation of the player, be it vehicles or teleporters.
Augmented or new ways of transporting materials - belts, inserters, pipes!
Belts are flat, and look OK when stood on (and we even get moved by them). Splitters and undergrounds are "3d" and it looks goofy when we stand on them. Loaders are usually 3d so they should probably have collision as well.
Good suggestion, added in 0.0.3