For some mysterious reason, there has been a real antipathy to linking context to relays. Topical relays are a superpower because you could just look through a list of relays and then select all of the ones for the topics you are interested in, and the relay moderators keep the posts on-topic and the spammers and trolls out.

Nothing stops there from being different relays addressing the same topic; you could write to any or all of them. You could have 3 different sourdough relays, 4 bible relays, a popery relay, 8 dev relays, a library relay, and a chat relays, and either combine them in your cloud relay, to save bandwidth, or stream some or all to your various clients and turn them on-and-off, individually, just by clicking checkboxes over your feed.