Evelynn passive: what if it only worked when near a wall?

Something like, "While Evelynn is within 300 units of a wall, she becomes stealthed after x seconds" and functioning the same as her stealth currently does. I read some comments about how Evelynn's power budget is mostly in her stealth right now, and while I play a lot of Evelynn (carried me from Bronze I to Silver II), I can agree her stealth's really good. Not having to worry about wards as much removes a lot of pressure off of Evelynn ganks, and even in ARAM she just pops up out of nowhere with no way of telling her Health/Mana levels or positioning. (Or her items after death until she's on you)

I thought about ways to make her Passive less strong while still retaining all the same functionalities, and I thought back to my Ragnarok Online days where Assassins could only stealth while hugging the walls. How'd that change Evelynn? I'd imagine some extra counter-play emerges where you can just stand on the opposite wall to increase the range from which you see her coming, and it'd give Evelynn brief periods wherein she's visible when skipping from quadrant to quadrant.

I imagine good players have absolutely no issue sticking close to a wall. If the range to be near a wall is too short, she's still very squishy so jumping into combat'd be a bit harder, whereas if it's too long there's no real point to such a change.

Would it be meaningful? Would such a change allow more power to her actual fighting kit?