Interesting issue and a tricky problem to solve. Knees are complicated. Apologies for being too personal, you didn't give anything away about your age. For myself I'm still in denial of being middle aged myself and I'm told niggles take longer to heal and I'm less flexible and stretchy.
Something I have learnt is that a muscle, tendon, ligament problems might actually be caused by a problem somewhere else. In other words a knee problem may have a source somewhere else. However, I'm not a Doctor or anything medical so I can't really advise with any authority.
On this forum bikes often get portrayed as being complex but really that's nothing compared to the complexities and wonder of the human body!