@meguey Indeed. I'm not aware of any way to gather multiple instances' timelines into one feed.
Such a thing may be out there, though! Mastodon is a coder's world, and there are many apps and tools I haven't used.
@wlonk @meguey I may be wrong but I thought we were talking from a user's perspective rather than an instance's perspective. So I might want to browse the local (not federated) timeline of a hypothetical PbtA instance, but I would also want to do the same for dice.camp, and maybe others. I don't think there's a way currently to see both on the same page (let alone the same feed). But perhaps what you're describing could accomplish this? I'm not sure I understand how.
A Mastodon instance for tabletop gamers.