I am going to continue to update this thread for the benefit of those whose hedgehogs may be experience similar symptoms.
The Revolution seemed to be working, and his quill loss slowed, but in the past few days his skin flakiness and quill loss has returned with abundance. I got a call from the vet this morning to let me know that his fungal culture has come up positive. It will be sent to a lab to determine what has grown, and from there treatment will be determined.
I've learned several things through all of this:
It is NOT always mites. Reggie was at very low risk for getting an external parasite. If your hedgehog is as well, and is experiencing similar symptoms, may as well get a fungal culture alongside a skin scrape.
There is a fine line between moisturizing the skin and making the skin overly moist. I've ordered humilac for use after all of this clears up.
I will keep everyone here updated on the official diagnosis. Thanks!