A buff to tenacity - something to make it not feel like garbage against knockups/displacements

There's been a lot of talk lately about how Tenacity means less and less because it doesn't affect the type of CC that almost every new champion in the game seems to have loaded in to their kit.

So how is this for a fix to tenacity? Current: Tenacity: reduces the duration of all crowd control effects at the exception of Suppression, Stasis, and Displacements.

Proposed: Tenacity: reduces the duration of all crowd control effects at the exception of Suppression, Stasis, and Displacements. Upon being CC'd by any CC that isn't reduced by tenacity (i.e. Suppression, Stasis, and Displacements) gain X% damage reduction for Y seconds (where X% is some balanced number that scales with the amount of tenacity you have built, and the time Y is suitably short [the purpose being you're still fully cc'd but you'll take less damage while cc'd instead).

Tenacity then becomes the premier thing to build against heavy CC, whether it's displacements or not. If it seems OP, you could change the damage reduction to armor OR MR adaptive based on the champion who displaces you (so if an AD champion cc's you, you get bonus armor. If an AP champion displaces you, you get bonus MR). Although that seems a bit weak as most often you'll get displaced by an AP champion then focused down by their ADC.

Thoughts? Please discuss, I haven't put too much thought in to this, but I think the general idea of giving tenacity SOMETHING against displacements may help it out a bit.