#Tenacity does not effect knockups, knockbacks, or pulls. 
(biggest offenders)
The addition to the URF buff implemented specifically to prevent permanent CC lockdown has absolutely no effect on such abilities.
_That should be changed. _
Side note: So there's no point in having it against Blitz or Ali even in the normal mode.
k wìx1 votes**I genuinely agree. Knockbacks and Knockups should be affected by Tenacity. Not a lot, but certainly something. **
Reikken1 votesI'd have named it "Knockups in URF", but yeah. It's pretty dumb.
The Ecdysiast1 votesI would've, but it also include knockbacks and pulls. Ali's and Bitz's other abilities. lol
Also included would be 
And don't even get me started on the gold deficit from being forced to purchase pinks on every back against Shaco.
afk soon btw1 votesFun Fact !
Vel'Koz E does not count as Knock Up and can get reduced by Tenacity.
The Ecdysiast1 votesStrange.