A mastodon UI shouldn't have a different entry path for lists, tags, etc and the half dozen other kinds of feeds. Just one button and see a menu of all your feed categories (tags, lists, collections, favorites, bookmarks, saved searches) they're all the same object... a list of posts and members, but made differently.
They should still get their own distinct edit screens tho.
Brought to you by me staring too long at "Lists", "Tags" as main menu options.