I made the following two videos about the use of supportive equipment when squatting about five years ago. I think that, except for editing and video/sound quality issues, and the considerable lengthiness, they were done well.
When wearing a suit, especially for a low-bar sit-back style, it is easier to slip into a relaxed posture when squatting below parallel because, by doing so, you stretch the suit less. The problem, of course, is that by doing so, you are taking strain off the suit and very likely putting it square onto your lumbar and knees.
The biggest nugget of the video is this (and I don't remember if I stated it exactly this way or not): When it comes to supportive equipment, THE PATH OF MOST RESISTANCE IS THE PATH OF MOST ASSISTANCE. It should be hard (and painful) as all get out to lower into a deep and technically sound squat with tight fitting equipment - if it isn't hard, it isn't doing much for you.