As Poser has L/R reversed axes to MMD, I used PMX Editor option to ''mirror'' model before exporting it as OBJ+MTL.
After some iteration, I imported at 2.0_% of original, scaled by eye by LaFemme vs the stairs. YMMV.
The two lighting panels glowed well when sufficiently dialled to ''super ambient''. Sadly, the ''Experimental Hall'' stayed dim. I could not make the default Poser lights ''play nice'', so turned them off and positioned a weak ''distributed'' light inside the room to help fill the deeper shadows. Also, I gave ceiling panels'' a paler diffuse texture plus some super ambience.
The gallery / corridor just stayed dark. I resorted to dialling its single-texture ceiling to super-ambient. Cost me those panels'' nice detailing, such as HVAC/AirCon vents, but the wide area lit proved a fair trade-off. Nicely illuminated both the gallery area and that end of the room.
I tried to capture the nice view from the gallery but, due to that now-white ceiling, could *not* find a camera setting that did justice to the scene. So, I moved camera to far corner of room. Rendered in Superfly with 64 pixel samples, ''progressive'', 64 Vol-bounces, 1024 buckets and both GPU cards. Took a while but, IMHO, worth it...
;-)
Given my hapless battle to illuminate this set, I''d rather position some low-poly Poser primitive rectangles against room walls and corridor ceiling, dial them to ''super ambient'' as generic lighting panels. Later, I''m hoping to edit the OBJ to separate / clone possible light fittings to independent parts. That should let me illuminate corridor while keeping the ceiling panel detail...
This is a nice setting. Thank you for the advice regarding lighting techniques!