In addition to lemmy.cafe and quokk.au and Tesseract on dubvee.org that have each defederated from it (though as Blaze mentioned they are all single-admin instances), iirc the apps Connect or Sync will let you block any custom instance you want (I don’t have either, but from what people say?), or the Lemmy alternatives PieFed or Mbin likewise plus they have neat features that Lemmy lacks such as Categories of Communities.
In addition to lemmy.cafe and quokk.au and Tesseract on dubvee.org that have each defederated from it (though as Blaze mentioned they are all single-admin instances), iirc the apps Connect or Sync will let you block any custom instance you want (I don’t have either, but from what people say?), or the Lemmy alternatives PieFed or Mbin likewise plus they have neat features that Lemmy lacks such as Categories of Communities.