Josh, Re PFS and VMO stims,
looking to create permanent improvements to VMO recruitment must start and end with attention to the source of the femoral nerve irritation that produces both the patella area referred pain and the altered recruitment pattern. That being the mid lumbar spine, L3. attention to the ongoing spinal protective control there , to eliminate paravertebral tone and it's consequences, will quickly and permanently eliminate both the altered recruitment and the patella femoral pain. The method with the best prospect of effectiveness is any variant of the maitland method ( mulligan, maitland or Continuous Mobilisation).
The VMO problem is only a symptom of a readily treatable spinal condition , best seen as a non pathological, protective behaviour of the spine.
Cheers