Hmm, now my question is.....to me it seems that the axles are to short BUT we are running the same rear control arms and have different wear marks and pattern. I believe either my adaptor (mas280 design) or my control arm settings differ from yours and this is why I am not following the logic of adding material to the stops. If I added material to the stops, I believe it would bind up. Also in the picture you show, it seems as if you are "testing" the movement of the axle vertical and I am not 100% sure that show the true movement when mounted horizontal during suspension travel.
Mark, what rear control arms are you running? Blown77Z, you think the camber in the rear pushes the axle inboard and outboard during adjustments. I wonder if the sound I heard at the track is....the axle slamming against the stops or the bearings slamming into the cage as the "guts" come in and out. I guess installing it all together without the boot and then mounting it to the car would be ideal.