Well the value of it is that currently the physics system doesn't make objects fall, ever. They teleport to ground without traveling through the space in between. Only unsupported objects would gain an acceleration so it really wouldn't burn up very many clock cycles unless you loaded a lot of objects onto a bridge and then dropped them all at once, for example.
It really wouldn't be computationally very hard to do, either. Currently the system finds objects which are unsupported and then looks down to the lowest z-level where there is ground, calculated damage, and moves them all at once. An acceleration based system wouldn't bother with that.
Current system:
- Is the object unsupported?
- Same frame: calculate distance
- Same frame: Calculate damage
- Same frame: Drop Object
- Same frame: Splat
Acceleration-based system:
- Is the object unsupported?
- Same frame: Accelerate downward
- Has a moving object hit something (ground, walls, etc)?
- Calculate damage
So you can see that it doesn't pile everything onto the main frame like the current system, rather spreads it out over time. Regardless of how many calculations it requires (not many, since gravity doesn't work like that as I mentioned above), they are spread out over many frames and don't need anything more complicated than checking things which already must be checked and adding a constant variable to an object's downward speed if that check fails.
But this is really about bows and arrows. It would be nice if there were customizable reload rates. That would mean bows, crossbows, and even exotic weapons like the Chokuno repeater crossbows would be be easy to make by changing the reload. Mods could make machine guns and a distinction could be made between a light, easilly loaded weapon and a heavy, powerful, but slow to fire one.