Sometimes, the "upfitter" (RT in your case) suggests/recommends/whatever slightly different alignment specs than does the original vehicle manufacturer. I've long thought that was because of all the "extra" weight they add to the unit.
I'd suggest you contact RT and ask what are THEIR alignment specs, and provide them to the facility you choose to have the work done - IN WRITING.
Separately, in our case (PW, not RT) I have always wanted to speak with the "tech" who will be doing the work to be SURE they understand that the undercarriage is lower than they usually encounter - even for a "remote (to us) city oil change. Even then, I want to SEE our PW go up on the "rack" to be SURE there is adequate clearance. In my experience, it sometimes takes some "blocks" at the rear axle to allow the plumbing to clear their lift. They don't believe it 'til they see it.
I much prefer to have a slightly upset "tech" than their simply offering an apology about the damage that has been done.
Sometimes a flashlight, a bit of persistence, and/to some dirty knees, keep our PW humming along just fine.
JMHO.
Cheers.