The thiaminase issue is something that has never been proven, only speculated. I have never seen nor heard of a frog that actually had a B1 deficiency.
I think that the problem lies in people feeding store bought foods. I think everybody should at least breed some species of roach, as that way you can feed them whatever your animals need. Powdered milk is a perfect source of of calcium for feeder insects. I know exactly what my animals are eating, as my feeders eat better than me.