Allow me to recommend these, sort of the monster Cadillac/Bentley model:
Nothing lightweight about these, the nice part is the way the thigh stabilizing attachment keeps them from rolling away from where you want them. It happens more with the hard face type.
I had total knee replacement surgery on my right knee last September. It’s been a net benefit but a bit of an ordeal. One thing that’s really lousy, it hurts and feels weird as hell to kneel on that knee. These pads make it bearable. The padding under the hard face really supports the entire knee area pretty well.
Spendy - $50 to $60.
https://tinyurl.com/4h5365vp
Also at Amazon.