Substrate to boost humidity

[SDA]

when I need a boost I put a shallow dish with damp sphagnum moss in both corners (so the bedding isnt constantly wet)

This needs to be told a lot more. You do not and should not need to keep substrate damp. It promotes bad bacteria, mold, yeast, etc and is not good for a snake to live on. Sphagnum moss in clumps in the corners does an amazing job to get humidity where it needs to be and keeps your cage from being a swamp