Nice poses ;D your back looks great. How high is the bar up your neck when doing squats? Could not really see it in de video. I think most people make the “mistake” of laying the bar to high in the neck instead letting it rest more on the back muscles. This could make you tilt forward when stuff gets heavy. Then when you come back up you might try to straighten your upperbody first (making it look like some romanian deadlift with a bar in your neck:p) before coming back up.