One of the main features of Darius Kazemi's Hometown, a fork of Mastodon from 2019, is that it allows "local only posting". This gives the users an option to post their content only with a small, limited group of people instead of spreading it widely outside of their social group. In addition to helping to tummel a smaller conversation this also prevents those who are more likely to suffer from context collapse of the groups social norms from engaging and potentially souring the conversation.

This feature could also be well leveraged for small private classroom conversations between teachers and students without leaking their personal/private data or conversations that ought to be small as they learn.

Could also be fun to limit the level of federation to the level of an academic department, academic discipline, or even a university. How might one define a group or groups of publics within Mastodon so that one could choose a level at which to share their content?