BP wants more rats

[Malum Argenteum]

Have you tried the hairdryer method for actually feeding , incidentally ??

I have not, but I don't have any snakes that are fussy specifically about prey temps.

If I were to switch to chunks, what size do you recommend? Is there a different substrate I could use during high humidity months when I don't need it to hold moisture?

For a BP with any size to it, I would (and I do) personally use the regular size of ReptiChip. That brand offers smaller sizes that are useful for smaller snakes, but the regular size would be best I think. There are other brands too, but the couple others I've tried I didn't think were as good (too big, too hard of chips -- might be more suitable for large snake species, which I don't keep).

I would just use that substrate all the time, unless there's some pressing reason not to.