Today ( actually yesterday ) I learned that there is software that does what Mastodon does, but has more features.
It is called "CalKey" which is a fork of "MissKey". It is similar to Mastodon, but with more features.
Mastodon, MissKey, and CalKey all run on ActivityPub, the protocol that makes federation possible.
All 3 interoperate. For example, someone I talked to using Mastodon told me about CalKey.
Same content, just different ways of getting there. Like using a different car to drive on the same roads, getting the same content.
Supposedly ( I haven't tried it ), CalKey has an easier and more advanced migration tool. Something to think about when the next Mastodon server ceases to exist or you don't care for mastodon.social and other servers embracing Threads.
Nach der Möglichkeit zum Abonnieren von #Hashtag s wäre es der logische Schritt, entsprechend die abonnierten Tröts zwischen den Servern auszutauschen.