I don't think you'll need the relocation TB bracket, but can you take a picture from the back of the truck that shows the angle of TB perpendicular to the ground with he truck level? i'd like to see how the angle looks like in your case. Measure you axel shift while you there as well. you should have a little more tire perhaps showing from your passenger side and the bracket could help mitigate that and be cheaper than an adjustable TB.
You can see this video for example to understand what the TB does and how the rear end moves side to side as part of it's normal arc
I'll follow the same approach from the long travel race kits available for our trucks personally (Dirt King or Gor Racing) they have beefier control arms, beefier adjustable TB, no drop bracket and their kits go higher than Carli. Now why the race kits are not concerned with what Carli is advertising is beyond me , i know i won't drill the frame side of the TB to place a bracket in there but if i needed to relocate the TB after a lift say 3" o more, i'll try to get the type that mount the TB from the axel, personal opinion from my rock crawling days.