Which SLR UCAs? With the econo ones I wouldn’t bother with the diff drop, maybe with the other ones but I would likely not bothered until I wore/broke something but that’s just me.

As far as the stock sealed u-joints for the drivelines there pretty durable and can operate at higher angles they you’ll get. Lasted over 130k in the rear of my pathy and 140k and still good on my X. I did end up eventually wearing out the stock one in the pathy partly because it was lifted ~10”, the pinion angle wasn’t the best, Detroit lockers, and all the wheelin’ I did. I went with a sealed u-joint again when it was time to replace, longer lasting IMO, less maintenance on driveshafts.

Although I never broke a CV I’ve seen my share of busted one and carried a spare. Most of the time it happens on full droop on a turn or with a little too much throttle up a waterfall, rock pile, or something like that. Did’nt seem to matter if they were running the older SLR UCA with the drop, CALMINI’s, AC’s etc.