Can there be too much heat when drying?

At what point does temperature rise over critical level while RH is high enough so that it doesn't dry too quickly?

I'm just interested to know what kind of heat damage could there be done to lower the quality of the end product except too quick drying.

If drying temps get too high I think the problem is largely cosmetic in that you'll likely get crispy critters and end up with product that crumbles too easily. Most of us try to keep temps below 85 or so. Crispy product is more likely to shed tris (and quality) and is less desirable commercially. If you do overdry it is simple to rehydrate and end up with round nuggets rather than crumbly dust. Put the crispy product in a large sealable container that has a large mouth. I use a 2-quart Tupperware bowl w/lid. .I put the product in the bowl and gently lower a small pill bottle that contains a paper towel that has been moistened. Seal the bowl and check every 12 hours.

Good luck, BigSteve.