And does anyone know if bfgminer supports the variable difficulty being talked about here?
Yes, for the past several versions. Your worker hashrate needs to be high enough, though. Roughly 20 shares/minute is the threshold I believe. I have a 1.6Ghps worker (~22 shares/minute) which never sees a difficulty higher than 1. A 12Ghps worker would see a difficulty of 8.
We have one bfgminer setup with 24Ghps total, so I'm assuming we should see the difficulty rising. What this quickest way for me to check on that, and is the difficulty level something I can set myself?
Thanks for your feedback...