The humidity for both of my boys is 85-88%, and I've kept my spinner in high humidity since I got him. Healthy, no signs of RI, zero issues.

Imo, higher humidity is better for bp's, as it is much closer to the humidity range found in Central and West Africa, where it's in the 70% and 80% range, and it also means you don't have to mess with it during sheds. As long as your snake is not consistently laying on a wet surface or substrate, and the enclosure isn't fogged or condensed, there's no cause for concern.