The manuals can't take a Calmini t-case gear set, only the Autos can. Maybe that is what your thinking of?
Calmini is going to say
on the LSD and manual, as they haven't done it. My thought, if the ARB fits, the LSD will too.
But why the fuss? Swap in Kick 5.12s and be done with it. Any increase in tire size will need it, and nobody will have an issue of whether the LSD or ARB fits.
As for survivability, it does okay with 31"s, and only locked in the rear. Lockers tend to break CVs, and the rear shafts will break if you get jiggy with it. I broke one. Not fun. Ran over $400 for parts from the dealer.