There is literally 0 reason to ever do a box squat. It doesn't help or improve anything. It doesn't translate to any movement pattern in any sport. It won't make you stronger at a real full depth high bar squat, it won't improve your form, and if you want a real world example to look at:
Take weightlifters and take powerlifters. Weightlifters squat to full depth repeatedly and knee surgeries and injuries in general are less prevalent. In conjunction to that, weightlifters are very flexible and well rounded athletes because they practice full range of motion and desire to keep an upright posture in their movements. This means they are trying to maintain stability and form in the most taxing positions of the movement. The very bottom of the squat.
Now if we look at powerlifting, we see more variations like the pin squat and the box squat. We also see squats to half depth. From there, the prevalence of knee surgeries and injuries in general go up. There have been hundreds of studies at this point showing that half depth squats are dangerous and achieve minimal if any effect on strength or hypertrophy.
Even from a logical perspective, at what point in the squat is the movement the hardest? Hint: It's not above parallel. So why would you train the part of the movement you can already do? You can already get up and sit down in chairs. You see many people in commercial gyms who are not well trained athletes, loading barbells with massive weights that they could never squat to depth and doing it to a box. So why keep training relatively the easiest part of the movement?
At the end of the day, squatting to a box is just an excuse to not improve strength in the hardest parts of the range of motion. Pin squats are fine because you are getting into position into the most difficult part of the squat and practicing the ascent. It's incredibly difficult to get out of position in the bottom, get back into position, and the raise a near maximal load. This movement actually reinforces the the motor patterns you are trying to do. It has transferability to many other qualities.
So do full depth and pin squats. Avoid low bar and anything above full depth.