The odd, and hyper-super-perfectly-inconvenient thing about the bricks is that the only way I have to export them, the normals get all jumbled up. Two triangles making up the same rectangular face could both be facing totally opposite directions. So while under ordinary circumstances it would be easy to select everything and move the normals in just a tad, all it results in is weird, random distortion. This went unnoticed by me for many years because the renderer I use renders front and back faces, so everything looked legit. But when I started to get picky and wanted the realism of visible separation between bricks, I was 'shoot-outta-luck'.
Indeed there are unthinkable numbers of polygons you never see, which is unfortunate, but my purposes are not game related and so I'm not super worried about optimizing all of that. I can still render video at a survivable pace using mostly unoptimized models. You mentioned explosions, and unoptimized bricks are certainly better for that purpose anyway.
@DarthSoban, can you investigate whether Stud.io exports bricks with proper out-facing normals? If it does, that's really all I should need!