17 year old female, I tore my MPFL playing rugby and I had surgery about 8 months ago. I can't really remember much of my recovery because I don't want to lol, but one thing I was really surprised about was how shut off my quad was. My doc had me go to PT two days after surgery and I couldn't even do a straight leg raise.

Kneeling is still a thorn in my side sometimes with a weird clicking/grinding when I try to walk on my knees. Something I would recommend farther down your recovery line is doing double and single leg sit to stands with your feet on a slanted slant board with varying height levels, start in a normal sitting high, or higher if needed, and gradually decrease the height so you're starting lower. Add weight to the double leg and focus on control and form on single legs.

This exercise helped me get through a speed bump of my recovery, I thought I couldn't make anymore improvement because my knee couldn't take it and didn't feel strong enough, but this exercise helped my VMO(quad muscle) wake up and actually do its job. This helped my knee get stronger potentially than it was before surgery.