Idea to improve Minion Dematerializer to allow users to execute low-health minions

With the current changes to cannon minions now causing a lot more "miss by 1 HP, you're screwed" moments, I feel Riot should take a look at the Minion Dematerializer rune. As it stands right now, it's basically comes out as invisible power, and doesn't end up feeling significant.

I have a way that it could be changed up to be more significant. The bottom line would be that if you spend all 6 Minion Dematerializers on a single minion type, you can then execute said minion type when they're below, say, 10-15% of their maximum health via basic attacks.

This sort of thing wouldn't be useful to marksmen or AD-based Champions who already have strong autos, but for mages (i.e. Lux) and the odd support it could prove quite valuable. But you would need to give up bonus damage against other minion types to make it work.

This specific method may or may not be the best way to go about it, but I feel that MD should grant users some means of last-hit execution attacks.