How to properly nerf Zac from Season 6 Rank 1 Zac player

My season 6 account is 'silas', its banned here

For how much power his basic spells have respectively (especially after given one of the best one point wonders in the game), his ultimate is far too easy to use now. Despite it having a plethora of viable uses and benefiting those with good intuition, Riot met popular demand too readily in terms of ease of use before people could adjust.

Coupled with this, his early ganking power is far too oppressive and reliable with his 1 second duration Slingshot combined with new Stretching Strikes.

With these two factors playing the biggest roles in his overpowered status, I propose applying a scaling max knock-up duration to E, and heightening his R channel requirement to 1.5s at all ranks, but heightening slow duration from 30/40/50 to 40/45/50% to prevent "walk outs" in earlier stages of the game.

(full channel E knockup 0.6/0.7/0.8/0.9/1s) This also makes further sense when you realize how easy it is to full cast E in early stages.

If he remains too strong after these changes, lower Q ratio or missile speed.