Riot, Bramble Vest can never be balanced
Only because there is grievous wounds on it. So it's a cheap item with 35 armor and 40% reduced healing if you AA them which is what the majority of top laners and ADCs do. Even if they don't have lifesteal most tops have decent hp regen or healing making it still good at pushing trades.
Thornmail having it is okay because it late enough in the game that you can counter act it soon after and it still is situational. But bramble vest is just too good in general and no amount of armor tweaks or costs tweaks can fix it. It will always be a useless item or a broken one.
I mean this seems to be a concept you have failed to grasp lately. Utility often is the biggest problem with most kits and items and it seems you understood that for Zoe. It would be nice if you could realize that for the rest of the game.


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would be too ridiculous early game to deal with.