Flaws in your squat technique will hold you back from progressing. Overhead squats can improve the squatting pattern and should be a regular part of your strength training program.
The overhead squat requires a more upright posture than the back squat and you're forced to execute the squatting pattern precisely, otherwise the bar would drop to the front or back.
Have a look at the video. You can see the high concentration level of the athlete and accurate execution.
Most of us poor slobs have jobs so we don't have the luxury of doing two-a-days, but we figure since it's summer there are a bunch of feckless college students out there doing one bong hit after another who just might be able to take advantage of this program.