I could really only see sense in doing the front half of the differential by itself If you had an extreme or Billet brace in the back limiting movement there.
I converted to the DIRS/Race brace so I also did the front half of my diff at the same time. I currently do NOT have the rear of the diff done as I have the DIRS back there and I'm waiting for an additional 4 wedges from BMR because my plan is to lock out all 3 bushings.