@mastodonmigration about hidden toxic accounts specifically : maybe following a pack could take into account your own instance moderation rules, limitations, restrictions, etc.
For instance : if you follow a pack with a hidden but known bad actor that is blocked or suspended on your server or by your mutuals, maybe it's just okay to drop it and not follow it.
Similarly: if you follow a pack with a hidden but unknown bad actor, we could keep a track that people followed through a pack were followed automatically, and simply stop the follow on behalf of pack subscribers without their manual intervention, when the actor in question reveals himself and starts getting blocked more widely.
Another way to put it would be: why not have follow packs merged with blocklists to create and update semi-automatically the pack for all the people using it?