As you know some guys like me are built for benching. Short arms large chest.
Other guys are deadlift guys short legs long arms. And squat guys like my friends are shorter( short thick legs ) between 5'3 to 5'9 at about 225lbs. Plus I have like zero flexibility in my hamstrings and my hockey ankles only like going side to side not foward and back. I tired the piece of wood under my feet and some plates. Also that dam bar digs into my neck does not feel good. I tried the black foam pad the blue bat wing.
Also my hips are also super tight like the rest of my body. I was born super tight aleast as I age I wont lose any flex since I strarted with zero.
I never used a weight belt or knee wraps other guys swear by them.
Just be careful adding weight to your lower back movements so not to tweak your back. I have wrecked my lower back from getting to crazy with power cleans back in the day. So bad it took me 5 mins to get into the car in the passanger side I couldn't even drive. Just remember you have to be able to tell the difference between a sore lower back from working it and wrecking it. Its a fine line which most of us who lift heavy will cross now and then and pay the price. By walking bend over for a week or 2. If you are doing squats the right way you should feel it in your legs not your lower back. If you feel it more in your back you are doing a good morning movement. Tom Platz is the man for legs and super low squats hams kissin the calfs.