When I bought my 2012 it was all over the road. The previous owner did every possible suspension upgrade there is! What I found was the toe was out 3/8”. I did a tape measure alignment and brought it in to 3/16” toe in. Dramatic improvement. The other was to lower the tire pressure. They were at 95 when I got it. They are now set at 86psi and the MH drives and handles incredible!
Now with that said it’s possible the steering stabilizer wasn’t installed correctly and it’s not centered resulting in the slight drift you are experiencing?