I'm definitely going to be getting a BP first, but I've been interested in BRBs for a while, too.

I was looking at care sheets for them, and there seems to be a lot of different info for them, I'm confused.

Some care sheets I read say that the humidity level needs to be around 70-75% and adjusted depending on whether or not the snake sheds well or not. Then I read another one and it says it needs to be kept around 90%? What? Then I read another one that said the 90% is only for babies? If this is the case, at what point would I be able to lower the humidity to ~70%?

What temperatures do they need? This is the most conflicting info that I've been finding. One care sheet says between 75-80 degrees with a basking temp of 85 degrees, another care sheet says temps above 85 can kill them (and if that's the case, why would basking temps be 85?)? So confused on how hot I'd need to keep the enclosure!

How big of a cage does a rainbow boa need? I haven't been able to find that info anywhere. I've been able to find how much the inside sq. footage should be, but I prefer dimensions.
My last question sort of relates to the cage size - but if I got two different size Vision cages (one for my BP, one for my BRB), can I still stack them?