by using motor.rotateFor you are actually using the build in motor encoders with the build in pid. it’s actually pretty accurate if you drive at like 50-60% speed and make sure your wheels don’t slip. you could improve the accuracy by writing your own pid loop. conner’s made some amazing tutorials that explain pid very well:
I’ve found the inertial sensor to be quite useful as well. sensors in general can be utilized to improve consistency. try using line trackers to recognize cubes in your intake and tray, and to line up with the goal zone. vision sensors can be used to aim at cubes for auton. ultrasonics can be used to line up with the field perimeters or other flat objects.