A cost for Knockups
As we all know knockup effects completely ignore tenacity. It's not like regular CC, where you would prefer to use it on some targets over others. You may prefer to knock the squishy carries up, but it's normally not a big deal if you hit other targets instead. It's not like you're using your snare on a 60% tenacity Irelia or something, it's going to have it's full effect regardless.
What if there was a downside to knocking up certain champions? I'm talking big champions, like Malphite, Nautilus, or high stack Cho'Gath. They could be naturally resistant to it, or perhaps have a small knockback or stun effect when they land, something to make CC placement a little more important in a team fight. If the effect works well enough it could even get a watered down version attached to Elixir of Iron.
I'm sure I've missed some pretty glaring issues with this, but that's the point of a board discussion! What does everyone think about this?