Leave the sleeves on. Research Evidence is inconclusive on their effects on knee proprioception/kinesthesia and Anterior Cruciate Ligament Loading At worst they do nothing. They seem to make you feel better tho so go ahead.
Do not rest in the bottom/hole. A passive pause where you take tension of your muscles and relax down onto your calves is inappropriate for you. This position places increased stress of the passive structures of your knee e.g. ligaments.
An active pause can and should, if your ROM allows it (see below), be incorporated. This is when you maintain full active tension on your muscles pausing at parallel using this tension.
If you had done ACL surgery rehab properly: Knee ROM, muscle strength & endurance, knee, stability, proprioception and various exercises you’d probably be in a much better situation now.
I wrote a paragraph somewhere about range of motion or mobility deficits in one body segment being compensated for in other body segments (will post if I find) but the point is:
Make sure you have adequate knee ROM to squat comfortably else you risk injury to your knee or elsewhere e.g. you hips and back. Also worth considering is whether ROM is equal on your left and right knees. Imbalance between sides can lead to problems long term. If you find deficits or imbalances get right onto fixing them at the same time as improving your squat form.
Make sure your form does not place excessive ROM demands on the knee joint perhaps exceeding the ROM with possess. This will probably require you rebuild your form using them vids posted. You’ll still have your strength that you’ve built only now you’ll be able to express it more safely.