_"We have fixed a 'bug' that stopped this working as intended. But we are afraid that working as intended will be stronger than intended?"_
Also, _(but I'm no expert)_, Im not sure that casting slightly over walls is what everyone is scared of about her?
I think its that her E gives her enough time to do whatever she wants from almost any situation.
Like Nightjar put it, you can accidentally land E, have enough time to think _"Oh shit, it actually hit?"_ re-position yourself, set up your entire combo, and still hit them before the sleep wears off.
Im absolutely loving this champ, but I think that with all champs _(not just her)_, if you want to land your full combo, you should have to fully commit from step 1, not just throw out spells and just wait for one to hit.
Taliyah for instance, you don't have enough time to casually throw out a W, see that it hits, and reposition yourself to use E. You have to commit to both spells pretty much from the get go. So if you land them, it's devastating, and if you miss then it gives your opponent a window to capitalise on your error.
With her long sleep duration and her short cooldowns, casting her combos incorrectly doesn't seem to give enough of a window for her enemies to take advantage of as it perhaps should.