30 years ago I had a raw squat at about 420… sometimes. My big flaw was that I wasn’t utilizing my posterior chain to its maximum. Coming out of the hole was ok but it was slow and I would drift forward over my toes.
I did a lot of reading (powerlift usa and books) but somebody I trained with that had a big squat… like 500 something lbs for reps off the street in work clothes and steel toes…was calling out commands for me.
When I unracked and set-up… he quietly told me to lift my big toes and keep them lifted for the whole set…and try and push the earth away from mysel….
This immediately helped me to set back more and drive my heels through the ground using my glutes.
As time went on, I learned to do this flat footed with toes firmly planted.
I said all that to say this: to this day I will squat occasionally (belt or otherwise) with my big toes lifted for the first rep or two to remember to engage my posterior chain.