I can understand that. I didn't realize that Reddit had that feature. I totally hear you that defaults stay defaults.

I may not have been very clear, but what I meant was that users would be able to create and share their own structures without approval or interaction from admins or mods, then admins would be able to pick and choose from those structures that users created and shared, and then the admins would have the option to make those structures the defaults for their instances if they wished.

However, I can see that having this kind of sharing structure could get pretty messy with tons of different structures around. I can also see that the structures could get outdated quickly. I also agree with you that it would probably be better for community creators/mods to self-organize with other communities to structure this.

I think you're probably right in your approach, but like I said before, it would benefit from being as simple as possible. Perhaps it would be the best to break down your ideas into smaller sets of features so they can be implemented in phases, or maybe even eliminate some features?

Like, for instance, why have permissions, hiding, or cross-community moderation? Why not simplify it to its most basic level: allow two communities to be linked with each other (at the request of either and agreement from the other for them to be in a specific hierarchy) and allow either community to rescind that linkage at any time? This link would make it so that users who subscribe to the "supercommunity" would also get all posts from any "subcommunities" (unless the same user has blocked any particular "subcommunity", in which case they would still not see that sub's posts). I think that just these two features would implement most of what I think we would both like to see, while being straight-forward. This could even be thought of as similar to a type of inter-community federation.

I'm thinking out loud too. :)