Something I have been asking for a while about the CV victory prevalence: how many of them are dedicated attempts at CV, and how many are unintentional? Typically a world conquest might end up in CV before, but that's not CV's fault. Nerfing the tech modifiers affects everyone, including dedicated CV. And dedicated, usually tall CV is a big risk: you lose the ability to hurt other runaway players. So a related question is: how many losses are dedicated CV attempts too.
As mentioned in the korea proposal, I'm a bit wary about tall play falling off. This might be unwarranted but several people had this impression, I don't know if there is more feedback about that. And I fear a nerf to dedicated CV is yet another nerf to tall play. And in the (to be confimed) hypothesis that many CVs are accidental, then this nerf won't change the fact that those games are already won, no matter the victory type. A related difficulty is how to enable both tall play and wide CV play, as these 2 tend to have opposed effects.
In the end, what CV needs is maybe more trade-offs, instead of blanket nerfs. I just wouldn't know which ones.