[GAMEPLAY] Kennen W passive (on-hit) is consumed when it shouldn't

I play a lot of Kennen and Twisted Fate, and those two champs have very similar passive abilities: Twisted Fate has his Stacked Deck (every 4th AA deals bonus magic damage), and Kennen has the passive portion of his W (every 5th AA deals bonus magic damage and applies a charge). However, I've noticed a major difference between TF's and Kennen's passive procs, happening whenever you throw an autoattack but the target dies before your autoattack connects. (usually a minion) I'll be adding a video of this bug sometime later today, if I get around to it.

Note: this bug was reported as early as 7 months ago!!

• With both champions, while simply stacking up their passives, if your target dies while your autoattack is mid-flight, your autoattack won't "hit" it (because it died), and therefore you won't get a stack towards your empowered attack. This is good and makes sense to me, since the stacks are an on-hit effect.
• With Twisted Fate, if your empowered attack is ready and you attack a minion, but it dies while the autoattack is mid-flight, the bonus damage is NOT consumed. This also makes sense to me and seems to be functioning properly, because the damage (like the stacks building up towards it) is an on-hit proc.
• With Kennen, if your empowered attack is ready and you attack a minion, but it dies while the autoattack is mid-flight, the bonus damage IS consumed, even though you didn't actually hit anything with it. In other words, Kennen's empowered attack is being consumed as an on-attack effect instead of an on-hit effect.

P.S.: while I'm talking about Kennen, could I ask that the "empowered attack is ready" icon on his buff bar be changed to something more visually distinct from the icon for "building stacks towards the empowered attack"? As someone partially colorblind, I have a hard time distinguishing the icon for "empowered attack is ready" from the icon for "1 stack towards the empowered attack" with just a glance.