how do I get something like this but in VSC or Obsidian? or to come at a slightly different angle, is anyone working on a version of this sort of product that can be self-hosted?
I'd recommend exploring Obsidian. It's inherently self-hosted : it's just local markdown files (but you can sync via git or their for-pay sync service). The plugin community is large and it has some of the best extensibility going. My suggested starting point (others' may be superior): switch to Minimal theme plus watch a few videos (search for 'my obsidian setup' and you'll find a broad range of fairly different tak…
The only reason I ask about self-hosted options would be to roll this kind of software out within a group environment.