An idea I had for a Gnar E rework

Alright, as all hardcore Gnar fans know, his E cooldown was nerfed to 22 seconds in patch 6.18 because "Gnar’s a little too effective at shutting down almost all forms of aggression - not just the really durable kind. We’re hitting his baseline effectiveness with respects to trading and gank-avoidance to open up the kinds of aggressive picks and pressure that should be key in punishing Gnar’s temper tantrums". Basically, Gnar is too good at avoiding ganks because of his double jump, and so the cooldown was nerfed. I think we can all agree 22 seconds is a bit absurd, and it clearly didn't do much for pro play, because Gnar was still played quite a bit in Worlds after the nerfs. Anyways, the context for this was that I thought that the reason Gnar is "too safe" is because of his double jump. The double jump allows him to get away with a lot of ganks where he really should be punished, but the ridiculous cooldown made hard lanes like Riven or Irelia that much harder because you have to play very passively when your jump is on cooldown. The double jump is also core to Gnar's identity, so it can't be removed, and I know all of us would be very upset if it was. So if we can't remove the ability that causes a balance issue, another option would be limiting access to it. In Mini Gnar, GNAR! gives passives to his Q and W (extra CD returned on catch and extra movement speed from proccing Hyper). The only basic ability it doesn't give a passive to is his E. I personally think it would be very interesting putting his double jump as a passive on his ult. This would mean that pre level 6, Gnar is much easier to gank. The jump speed could scale with rank, making Gnar just as powerful late game, but much easier to gank early on. In compensation, Gnar could have his E cooldown lowered, down to something like 16 seconds at rank 1. One potential problem with this is that it could cause Gnar to have too hard of a powerspike at level 6. I doubt this would really be a problem, seeing as it doesn't give him any extra damage at level 6, just more re-positioning tools. Another problem is that it would make Gnar too weak. However, I believe that an appropriate compensation in the E cooldown would be plenty of compensation. A third problem is that it could make it more difficult to play against Gnar, since the distance scaling with rank would scale with his level. Rito really doesn't like forcing people to learn multiple different ranges. I would love to see what feedback you guys have on the idea.

P.S. Yes I am biased because I like Gnar, but I'm trying to be objective here. If I gave any suggested numbers, it was just to have a concept, not for actual balance. I would like feedback on the general idea, not the tuning of Gnar.