I had the TSB done today - major improvement in the steering, no more fighting the steering wheel. Supposedly the new box has already been revised and I had the latest revision installed today. It was ordered by my dealer on 12/7 and arrived at the dealer on 12/21. My Jeep was the 4th one at the dealer to have the TSB done and I was told my Wrangler needed it a lot more that some of the others.
My steering and box is very close to spot on. Two weeks ago I got a call from FCA. I didn't want to shoot myself in the foot about gettting a better steering box(assumed) and now have an appointment for 1/4/21.
Since the call, I've been reading every thread, on every JL forum about the metal replacement box. I have found no info as to this metal box being superior to the aluminum, if the aluminum is in spec and functioning properly. I've found nothing about better internal improvements. Some folks speculate the aluminum box is inferior as to heat and expansion. If that was so, all the alum. boxes would have an issue and they do not. The replacement metal boxes are working better for folks with bad alum. units and they are cheaper for FCA and thats it.
I am canceling my change out. If/when my alum. S.B. loosens up, I will replace it myself for a $250. metal box (because I'm cheap)and move on.