There isn't really a maturing time, as the frogs waste can help contribute to the growth of the good bacteria within the substrate. I'm really not sure how often these frogs defecate or how large their stools are, but you might need to clean up some on occasion because it can get overloaded. I'd imagine that too much waste in there could be bad for these frogs since they burrow and probably take in fluids through their skin...(please excuse my froggie ignorance, I'm a reptile guy LOL)

The fuzzy things in the cricket box are actually dermestid beetle larvae (usually). They really only feed upon death, so they likely won't contribute much to this project. I'd keep them with your feeders where they can feed on the dead bugs to help maintain a slighty more sanitary feeder environment.

Your standard earthworms are fine, I wouldn't go overboard with them, just a couple in there will be adequate due to the small size. Be sure to obtain these from a reliable source though - because these could be eaten you want them to feeder quality.

Again, can't guarantee that it will work 100% with this species of frog, but the substrate should be ideal for them even if it doesn't bioactive correctly (I understand they fair well in coir anyway). Best of luck to you! = )

Ps. Plants can help contribute to the project as well, I'd look into some little ones that would able to survive in this kind of environment. Springtails and isopods are excellent harmless additives that will help feed on decaying matter and aid in inhibiting mold growth.