Kha'Zix Rebalancing idea?

's passive, Unseen Threat, deals 14 - 150 (based on level) (+ 40% bonus AD) magic damage on his first basic attack after the enemy team has lost sight of him. This passive, along with , allows him to weave in and out of stealth with a new burst every few seconds, allowing to nuke any target he pleases even when they're not isolated.

Personally, I think his levels of burst are fine... on a target who's caught out. However, his being able to proc his passive several times in a short timeframe even on non-isolated targets feels kind of off, given he's about pick potential. So... I thought about this:

Unseen Threat's damage reduced to 7 - 75 (based on level) (+ 20% bonus AD) magic damage on his first basic attack after the enemy team has lost sight of him. This damage is increased to 14 - 150 (based on level) (+40% bonus AD) magic damage on isolated targets.

This doesn't solve the issue of his ability to proc several times over the coarse of a fight with an R evolve, but should make him a bit more reliant on isolation to burst down a target before they can react. What are your thoughts?