This is something I once told Toons about, and that he attempted to fix... But i think they've returned. Sheer wakeup time variance. Enough to throw off oki games and really ruin an attempt at mixup.
In particular, there's one skill which exaggerates the issue to an extreme... Seismic Toss. See as follows:
(For reference, each screenshot was taken immediately after the opponent's wakeup animation finished and they stopped being tinted white)
For some reason, it makes it to the point of where you can nearly fit an entire neutral jump inbetween Kril and Gem. It's not frame data, and it's not entirely falling size... So what could it be? But more importantly, does anyone else think it's an issue in the first place?