Feature Proposal: follow your main feed from a different instance

[mayel]

Is your feature request related to a problem? Please describe.
If I sign up to a Bonfire instance and follow some people (or join some groups), but my main instance (where I regularly read the feed) is elsewhere, besides manually re-following the same accounts there, or using the account migration process to copy them, I may miss some updates from those people/groups, especially if I have followed some new ones and haven't repeated the process.

Describe the solution you'd like
Follow my main feed from another instance. This could hypothetically take the form of a private profile (have to request to follow, and feed only visible to followers) that once followed privately boosts any activities that you'd see in your main feed.

Describe alternatives you've considered
A way to "sync" followers (eg. automatically running the account migration process regularly), but that'd be inferior because it'd re-request to follow any people with restricted profiles or closed groups.