Depending on what kind of stand you use you could make something to raise the seat up. This would lessen the angle of the bend in your knees.
My right knee gets sore when it is cold. Too many years kick starting stroker motor Harley's

I use a really thick seat pad or twowhen I'm in my ladder stands. I'm only 5' 10" and the seat is still too low compared to the foot platform. The foot platform is also real small and close so you can't strech your legsout much.
This also makes it easier to stand up with bow in hand.