Need to do some research, but anyone know off hand which #activitypub implementations support shared inbox with a different hostname? (Or which go out of their way to reject that?)
I'm thinking about vhosting, so it would be possible to switch providers, but obviously if you're hosting 1000 fedi domains on a single server, you'd prefer one shared inbox to 1000.
You can follow the Kbin Magazine ‘test’ by searching and following: @test. You can also post into it by tagging it.
If you are already familiar with #Chirp and #Guppe groups, it works similarly. Follow it to get content, tag it to post content and share with everyone following the “group”/“community”/“magazine”.