Kha'Zix ult evolution

I've seen a lot of threads asking Kha's ult to be made into an ammo system which I think is an awesome idea. Right now (as far as I know) not a lot of people evolve his ult because the other evolutions are just so much better in comparison.

What if evolving his ult made it into an ammo system instead of giving you 1 extra stealth charge.

Thoughts?