Maybe bin them by last seen, then check more recent bins more frequently. This ensures that people that are only on a couple times a week get almost the same priority as those who are on daily. What happens if you follow 2k people who post all the time? What about 10k? Damas won't have this problem, but what about specialized clients that follow 100k+? We might need to add separate commands to the protocol to upload filter sets that can be referenced in queries. Or maybe a way to reference a follow list note as a query param.