A follow-up to close the loop! The Yukon went back to the shop on Monday this week. The odor was found to be coming from the front differential vent, overheated gear lube! An oil sample was full of metal, so they pulled the front diff, took it apart and found that the adjustor locks had slipped, removing all backlash from the gears and chewing up the pinion gear while destroying the bearings and ring gear. The blown strut was coincidental, but extremely fortunate! All new parts in the differential, hopefully with the adjustor locks staked, and the stink should be gone.