Could you do the knee extension exercise?
You sit in a chair and lift your lower leg until it's level.
That was the one exercise that gives the greatest benefit.

I have moderate to severe spinal stenosis and 35% scoliosis curve and lift weights.

I wonder what kind of weight lifting it was told you are not allowed to do. By doing weights and core exercise, my scoliosis has also not progressed and my bone density has improved. I do not do any weight lifting that involves me doing weights that go overhead, though. Just a thought, maybe to get clarification on if a bit of lifting is of interest.