I know that a few of the guys in my suboxone program are rx'd tramadol for pain in addition to suboxone. Its a tricky slope as you know, and most docs are hesitant to rx pain meds to suboxone main patient.
I tooled around the web for you and you are right that there are not many resources related to this topic and I would think that it would come up often. Many people I've met on suboxone treatment deal with chronic pain on a daily basis and became dependent on opioids because of it.
I will ask around at my next group session, good luck and hang in there!