I've asked our Dana rep to see if they can get us a list of differences between the Ultimate 44 IFS and the standard 44 in the Sasq and up models. The only thing different I see listed is the housing is cast-iron, iirc the OE 44 section is aluminum, but it's been awhile, maybe I'm not remembering right.
For the JL/JTs, the aftermarket Ultimate Dana 44 live axles gets thicker tubes, thicker brackets, not FAD, cromo axle shafts, bigger yokes etc. It'll be interesting to see what (if anything) they've upgraded over the OE Bronco 44 IFS section.
Looking good 2BB!