Hi Dean.
I'm pretty new too, but I have seen quite a lot of debate on the substrate front with wood chips almost always losing to any other form of substrate besides sand.
Basically, at worst wood chips can potentially be toxic. But there are other issues, like mold, the rough surface irritating or damaging the T, complicating maintenance, and not being very effective in trapping moisture for slow release to up the humidity. Then there is burrowing which is difficult or impossible in wood chip and many more.
Personally it makes sense to me to have some kind of substrate that mimics their natural habitat. I use shredded coconut husk with varying levels of dampness for different species. For example, I keep more moisture in the B. Albopilosum's peat (which lives in the Honduran jungle), than the N. Chromatus, which is a grassland species.
I hope this helps!
I'm not impossible. I'm being improbable.