Buddy has the TBAC Dominus on his Kimber Mt ascent in 6.5 Creedmoor. Full length barrel still. Shoots great! It may CHANGE your load tune or point of impact, but will often shoot better , probably honestly from having a little more weight making you hold better and manage recoil better? Maybe? Or maybe it tames some of the nodes? Heck if I know but I'll bet it shoots at least as well as plain barrel with a proper load worked up.
The thing about it not shooting good cuz its skinny with a thick thing on the end....how much experience and proof of just that happening is out there?! A lot of things get spouted off as fact when it's all hearsay. Chop it a couple inches if you can, closer to the flutes, and have it threaded and a shoulder adapter put on by Shaen. What's the baddest thing that'll happen? You will sure learn something.