@rothko @hazz223 @LilithElina No other users on your home instance or any other instance are affected if you bridge your account – unless they bridge their account, too. If you boost a post of an un-bridged account, it won't show up on Bluesky. It's strictly opt-in.
@rothko @hazz223 @LilithElina Just compare my bridged profile page
https://bsky.app/profile/katzentratschen.mastodon.social.ap.brid.gy
with my original profile page
https://mastodon.social/@katzentratschen
Moreover, only public posts are bridged.