[1MachineElf]

Most mastodon servers don't limit discussion to a central domain of topics.

If you still feel limited, then the solution to your problem is to have multiple accounts for the mutually-exclusive communities you enjoy. That's what people do on Reddit, Facebook, and Twitter with their alt accounts. Keep that in mind whenever you encounter someone online using an anime profile pic.

The major factor I look for when choosing a mastodon instance is the business model. The vast majority are free, which leads to either limits on registration, ads, or spammy free-for-all instances. I want to join a mastodon instance that I can pay for, as a control over these types of problems. If it can sustain itself through membership, then the experience and policies should be relatively stable.

For the above reasons, I use mastodon.green.