Mite eggs will hide anywhere they can fit. They can fit anywhere because they are tiny. It's impossible to clean fancy substrate, bark logs, climbing branches, and the various other things people put in tanks for their own viewing pleasure. The snakes doesn't care either way. That's why you want a minimalistic approach combined with soaking the snake and treating the enclosure. The tank should be as bare as possible so you can clean every square inch. That's why paper substrate and plastic bowls/hides work the best in preventing and curing mite infestations. If you insist on adding the other stuff just wait until you are very sure the infestation is gone for good. Good luck OP!
Regards,
B