I realize it's been a while since I updated this.
All my poly sets have culled or died, but my sample size was only 5, so I still can't say for sure the mexicanus from this spot are pleometric. I have around 35-40 colonies now, most of which are in tubes. I have 3 in hearths, and 1 in a random slope nest that I made, though she doesn't seem to like it very much, I'll move them out soon. As of now, all of them have between 10 and 30 workers, with my very best one having well over 40 and at least 5 repletes. I am a bit behind the others, due to my slowness in tubing them several months ago. Their second generation has pupated, and I expect them to eclose in about a week or so. I can try to get pics over winter break, when I will be designing nests and figuring out the best way to house and heat all 40 of them lol.