At present, I think I have very little to add to my initial post:
1) #BanBarcelona, #BanTheMetaHordes.
2) Construct or forward to a landing page for #Metas asking a user to create a native #Fediverse #handle WITH a compulsory #introduction (no easy way in for intelligence-steered bots from #Russia, etc).
Other than that: protect #Mastodon's and the #Fediverse's culture by avoiding the #Metas' onslaught by there sheer numbers:
https://mastodon.social/@HistoPol/110007609833914742