I suggested some fishes that would co-exist with the crayfish to do away with the torn BSFL particles. Seems an acceptable solution.
I think you would need very small fish so that they didn't compete for whole larvae. Gambusia come to mind, but they would reproduce quickly. Perhaps excess Gams could be converted into crayfish food.
I would love to grow two or more isolated groups of fish at some point to test for growth rates using BSFL compared to other feeds. So many grubs, so little time.