It’s amazing what you can read on here.
Modular walls are GOOD for static lighting. You can tweak the lightmass params to cope with that.
It is possible to build blueprints with what looks like static lighting, but the method escapes me for the moment. But I do know that they are in the details panel of the door mesh! 
PS the lightmap res on that main wall it too high, of course… 
PPS: It could be this combo
