Really nice video and very good tests which actually allows you to better understand what’s going on there.
I also tried two different methods:
One is to build a 1mx1mx10cm blocks to be used as modular parts and a unique mesh ( with the chamfer trick which works good ) for each single room and a big ( external ) mesh to enclose all those meshes, since they’re one side.
I still find difficulties to get nice clean lighting but mostly because I’m trying to get very good and detailed contact shadows for furnitures, and the way I’m doing it is to mess with the indirect lighting smooth and static level…
It would be interesting to get the files you tested available to check so that everyone can see the various situation and how the lighting behaves using different approaches.
PS: The unique mesh with the chamfer, the lightmap is 2k or 4k?