Why would you take Vault?

So the mighty warrior, who at 10th level can do some amazing stuff, might want to spend one of his maneuver slots on... jumping 1-10 inches higher?

Does anyone's game have that level of granularity in measurement?

Let's assume a fighter with strength 18.

"I make a running leap for the ledge"

"OK, you can jump 7 feet, but my notes here say that the ledge is 7 feet 5 inches high, roll your Vault maneuver"


"Nope, sorry, you fall to the ground"

Does that sound like a likely scenario or even much fun? Does anyone really make notes along the lines of "this terrain thing is X feet Y inches tall", or do you just use feet? If you just use feet, then the high jumping part of Vault is literally useless because you can never get an extra whole foot out of it.

I would say just make it a Strength check and add the max of the dice rolled to the result...

I guess another option would be to simply say you get +1 foot of vertical jumping height for every die spent. This seems fairly balanced and also useful.