I appreciate the input that I receive from everyone on this forum, plus my local PT community, and my doctor.
I am a retired engineer, I have a process for solving problems, my knee is not a problem per se, but attaining my mobility back and the ability to hike a few miles a day is my goal. I'll take lots of input, and use my judgement, and knowledge of my body, to reach the goal.
Balance is the key, as it is with many things in life, too much one direction or the other causes imbalance.
I do think that the "no pain, no gain" mindset is wrong. Even if everyone else out there say otherwise.
My OS told me this: if your knee is warm (compared to other knee), it's still healing. If your activity makes it warmer, it will swell, or swell more. With swelling comes pain.
Now the balance question: daily activity, plus X exercise is the right amount, plus 2X exercise is too much.