With a squat 2x your body weight and a vert of 24 inches, i would say you would need to work on plyometric ability more, do lighter stuff, try to stretch and contract the muscles as quickly and forcefully as possible. Although there is always a temptation to train heavy, since it’s more tiring, training light is important for building tendon strength, and you are able to do more reps. If you really want to do the heavy throws, do both heavy and light, throw the light ball after the plates ina separate set after for a ‘contrast’ effect
