I exported your .bsp to model with lightmaps, models are lightmapped: https://imgur.com/0hemZen
Even those, which you were not asking for :) This is known issue: > 1024 vertices push model surfaces to meta routine, which enables lightmapping.
Regarding to lighmapping quality (visible seams), this is general q3map2 problem. Enabling phong shading should help, also may be -trianglecheck for 'light bleeding' issue.
This should be improved once we get what's going on there, at least that 1024 limitation should be applied to separate surfaces of model, not a whole.

Loading folder with 137 512-1024 textures take a few seconds here, which seems to be realistic case for models. This is slightly too much imo, considering that models have to be loaded too.
I found some 50-100Mb models laying around in setup here. This is another topic, if to/whether it's possible to quickly evaluate if preview loading would worth the time spent/memory consumed.