Just from experience: faster cooking? Personally if I was using your temps (and I would) , I'd check after 3.5 hours if I believed the advertising. As backs usually take 4 to 4.5 hr, that's a starting point.
What is "faster"? Unless they provide some guidance, I'd take that term with a grain of "rub"

and just monitor them at the 3.5 hr mark. Obviously you can check earlier.
AND what is "extra tender"? Look on the package. Does it say "enhanced" or something similar? If so, that would be the last time I bought them. Don't need injection (plus all that extra salt).