All good! You're right, they aren't, at least not where I did connect them. This was the only way (I'm aware of) to have a single outline for both complexes. Let me know if you're aware of a better way - possibly through a multi-part multipolygon perhaps? I have added the last remaining building (above the tunnel entrance with a rounded backside) in the meantime, which looks like it reaches all the way over to the South Building, solving the issue for now.

I've also added most paths around the back and side, gates, lifts and additional bicycle parking. Let me know if this is a good state for now for me for us to close this note.