I like the idea that tags could facilitate a sort of one-to-many and many-to-one relationship structure, where a pickle community could say it is related to "Canning" and "Cucumbers" among others, and potentially populate in the feed of someone interested in prepper stuff or in the feed of someone interested in vegetable gardening. I'm sure I'm not using the DB terms correctly but they feel indicative of the modular structure this could allow.
I like this flexibility better than the idea of a consolidation of subs into one themed silo, but I could be misunderstanding the structure of the mulit-reddit proposal if it allows for this.
I imagine it would be something like the wireless energy beaming tech in this TED talk: https://www.youtube.com/watch?v=RxrB7PDLJ18