I wouldn't really worry about RI but I would be careful using damp substrate 24/7 with no dry spot the snake can get to as that can promote scale rot which would be bad. Be careful feeding on reptibark as well since I have read people that have had their snakes grab a rat off it and get a piece of that stuck on a tooth. The snake needed owner intervention to get the piece of bark out of its mouth and I would be worried about the snake eating a piece if it is a smaller snake as something like a big chunk of bark isn't going to digest or pass as easy as a few shavings of aspen. I personally use aspen and all of my snakes have eaten some here and there and they are fine. never used reptibark.