Not OP, but the Sign In button is for GitHub on Zed. Which conflicts with GitHub sign in for any of the other AI agents, so you have to pick only one (the others will time out and do nothing after the first).
On work machines I use the corporate Copilot login, so I just have a permanent Sign In button in the upper right that doesn't function and can't be hidden.
Also I don't want to pay with my private data from some of my systems. So I don't ever want to sign in on those systems and just have a useless button sitting there.
Everyone knows that when a company pinky promises they won't collect your data and they'll keep things private, it means absolutely nothing. Unless it's impossible for them to collect your data even if they wanted to, all promises, especially from start ups, are worth less than the non-existent paper they're printed on.
Also I don't want to pay with my private data from some of my systems. So I don't ever want to sign in on those systems and just have a useless button sitting there.