mm..I wish there was a really immersive version of this, something that looked like the map in Crusader Kings 3 but which let you zoom in on what was actually going on in every place at every time. I'm a map junkie and collector, and like to read historical atlases cover to cover. This is cool but it could be so much richer. I didn't take the time to seek out inaccuracies.

If everything is in Wikidata then you can probably do that. It is always going to be a bit hard to get the polish of the data there.

I am a firm believer in that good visualization gives you better data. You can probably get a lot of detail mapping of data in wikidata if you make a map that queries "things happening in BBX during these years)