Thank you so much everyone for offering your wisdom and advice! After doing the "repeated pressing of switches to discharge static" it seems to have solved the issue in all but the Darkglass B3K, Creation Audio Labs Grizzly and OneControl Iguana Looper. Not a big deal as I have a second B3K and ordered another Grizzly, but the Iguana Looper is making it difficult using all of them again. One of the dudes at Creation Music Labs advised me to use some CRC Contact Cleaner on switches and pots to try and clean them out, which I'll do as soon as I can.
The pop issues seem to happen on these three pedals no matter if I'm using active or passive basses, different amp heads, different cables, the pedals by themselves on a OneSpot power supply and new instrument cables, etc. The only thing I haven't tried is a different speaker cabinet but the pops are evident in both my main speaker cabinet (a Bergantino HDN 212) or the headphone outputs I use for silent rehearsals/woodshedding.
Gonna have to put this issue on the back burner for a bit as I played a disrespectfully hot outdoor festival over the weekend and spent all evening Saturday and all day Sunday recovering from heatstroke, which further delayed my work for this week as I'm car shopping (WAY less fun than troubleshooting gear, I assure you!) but I'll be sure to post whenever I find a solution!