I wanted to post an update. This same bin is still going strong two years later. This week, I got in some more leaf litter and organic substrate and mixed in to refresh the soil (because they like to eat up all the leaves and such). I also wanted to try a different cleaner population, so I ordered some additional cleaners from Ready Reptile Feeders, adding in dermestid beetles/larva.
Finally, little Kenyan roaches (Blaberidae sp. "Kenya") have been added to the population. I'm hoping they'll get a foothold and give me some tinier feeders for juveniles next year.