The problem with RI is it covers a huge range of problems there are tons of bacteria that can cause respiratory issues and a handful of flora that can do the same too. There is no one cause it is almost always combinations of things. Low Air flow has been known to exacerbate the issues. The typical condition is low air flow being used to get the humidity up and especially when there is a huge difference from the room to enclosures. Personally I keep my snake room at 60% add lots of holes and everything is perfect. I know many whom just place humid hides and lots of airflow and deal that way. The idea of chocking off the airflow and using the moisture in the exhalation of the snake to raise humidity seems completely crazy to me.