I've been doing a bastardized version since I moved. I'm going to get the finishing touches after I get a bigger cage for Cassidy. He kills the plants. His last shed was beautiful and the soil just smells like earth.
This makes keeping humidity up much easier. I do have a drainage layer. Very rarely do I have water in it, and what I see is just condensation. I've read that it's typically optional for a bp setup, but I'm waiting to see how winter goes before I form any personal opinions about that.
Even had him to the vet recently and my vet has gotten a recommendation for topsoil as a substrate from another herp vet.