I've used Warbonnets almost exclusively for many years. I own I think 7 and I've never experienced the calf ridge pressure some talk about.
Well I just watched Blaze's excellent video on cold weather hammock systems and he explains very well why I don't get the pressure.
See for some reason I got it in my mind long ago (and I think per Warbonnet's instructions) to keep the head end lower than the foot end. I've done that for other reasons (other than calf ridge pressure), reasons like helping the lymph return to circulation, keeping from sliding forward (as Blaze also points out); but by lowering the head end the chances of CRP (calf ridge pressure) are small to none. Check out Blaze's vid if you haven't already: