In case anyone was wondering...

Figured out what the problem is.

Lazy EGR valve. Hangs up every once and a while and takes about 10 seconds to fully close once vacuum is pulled from it (letting off the gas).

Temporarily disabled EGR system. Truck runs much smoother and the idle shenanigans are gone.

Fear not any AlGore disciples, I will be replacing the EGR valve and vaccum bits with one off my parts truck very soon. (Gotta keep teh earf from warmin ya know).