Sub-Feeds would essentially be themed feeds under a specific # (i.e #crackden, #insilico, #everwinter etc) This would allow RP sims to use Primfeed as a RP tool and gain Primfeed more users that have yet to hop on the bandwagon. It could also function as a host for micro-communities that arnt interested in the grid-wide feed.
Under Feeds it would add a 3rd option Sub-Feeds, and here there could be a dropdown where users could save their favorite sub-feed titles. They could track events on the sims or watch the active posts from other RPers and their doings on sim as if it were a real social media for their RP.
Ideally it would be nice if the sim owners could apply for moderation rights over their sub-feeds if they're well established enough, and maybe change the default colors of their and add a titler card to their sub-feeds.
Give them maybe 3-4 moderation slots they can assign under their leadership, and this would provide free live moderation for this section of Primfeed as well.