Idea for Vayne W

Although I am perfectly fine with Vayne's W as it is, I see lots of people complain about her and her kit. I think that a possible way to limit her would be through her W. If you read what her W says, it says

"Vayne tips her bolts with a rare metal, toxic to evil things. The third consecutive attack or ability against the same target deals a percentage of the target's maximum Health as bonus true damage."

I think that, following the fact that it's supposed to be a "rare" metal, she should only be able to have 10 or 15 on her at any given moment. It should be stock, however, when she shoots someone with a silver bolt, it should drop to the ground and she should have to walk and pick it up to get one instantly or wait like 5 seconds for another one to appear in her inventory. This would make it harder for her to infinitely kite and melt frontlines, and it would make it so she doesn't get an insane powerspike after BoTRK.

What do you guys think?