Thanks for sharing, Sam! I’ve incorporated some of these already since the first time we met 
I’ve been using emojis in my space names as a namespace. I guess your examples of sam/ideas and sam/future are omitting them? 
I’ve experimented with your home space idea. I’ve tried an “Inbox” and then also having a space per week for work (sample here). I also create scratch spaces too. And then I have a “digital garden” for capturing ideas publicly. So, I haven’t settled on anything – still experimenting.
My home space also contains links to my other spaces, grouped by their area of interesting: this has some overlap with the namespacing, but it’s helpful to have a more freeform way to manage a directory of my spaces.
That’s a cool idea I’ve been meaning to do as well. Have you found navigating to linked spaces from home preserves some of the benefits of laying things out spatially? For example, if you look at these linked spaces as children of your main home space, does it “feel” like you are drilling down into a topic? Would being able to zoom back out help with this? I just wrote down some thoughts in this regard so I’m really curious lol.