what about backward stair climbs.
I definitely cannot do the atg split squats trying to touch my hamstring to my calves as hips feel restricted in getting that far and I can do it with front leg elevated to about 12 inches high but heel comes off the floor and back leg hip is tight and a little painful during the stretch.
but I can do seated good mornings without problems till chest goes beyond knee level.
That would be the same as Peterson setups
But if your knee hurts I would start with backwards walking or reverse sled drags as the amount of reps you can do is way higher and it's less likely to cause knee pain with shallower slopes or lower loads
You should be progressing step by step, not sure why your jumping into the more advanced exercises when your knee hurts...
All you need to fix the knee is the backwards stuff, then add in lower step ups, and progress the height if pain free, then add load.
Couch stretch - I do the one on a couch not the wall
Soft tissue work if needed
After a few weeks you should be good to go.
