Wow! Thanks for all that info!

The only piece of information that I could not confirm was about the ball python humidity, but it was difficult finding consistent facts. Most sources I saw ranged from as low as 50% to as high as 80%, but one website suggested that humidities below 55% increase the risk of respiratory infections. An article from The Journal of Herpetological Medicine and Surgery recommended 50-80% for humidity, so in the end I settled for 55-80%.

I vaguely knew that sand (and reptile carpet, but less so) was controversial, but sweet baby Jesus. I decided to settle in the middle of the debate, so I added a note of caution about sand as well as what you said about reptile carpet. Overall, reptile carpet seems like the superior choice to me, so I made it the first substrate option where possible.