Mastodon Feed
This "sub-identity concept" is nothing new. I remember reading a blog post by the founder of #writeas where he discussed the importance of maintaining multiple digital identities (I'll try to find the post).
It helped inspire my #digitalgarden multiple "plots" concept. But hopping across plots on my site still *feels* like my site. And I'm under no disillusion that I can capture 100% of someone's attention on any given day.
But #Meta could.