I usually cook my butts at 275, reduces the time considerably, and I have never noticed any difference in taste or texture. If you get in a time crunch, you can add some moisture and foil while still on the smoker. Wrapping, toweling, and cooler-ing is a big benefit.
I have injected, but never used that particular injection. Even though it is enhanced, you'll be fine. No need to brine it, though.
IMBAS Certified MOINK Ball maker and IMBAS Sgt. At Arms.
And now, brethren, I commend you to God, and to the word of his grace, which is able to build you up, and to give you an inheritance among all them which are sanctified. [Acts 20:32 KJV]