I have the same exact issues on my 08 XC chassis.. 35k on it
I too fought the wander in the lanes.. have safe T plus installed but never could get it to center correctly.
I also have Toyos, but mine are M177 big brother to yours.
it is currently in the shop for repairs
here is what was found on mine,
Bell crank, sway bar bushings, both being replaced with super steer parts, bad alignment, and KING PINS yes the right side was flat shot, bearings were allowing slop in the right wheel... thus causing the vibrations and wandering...