About 3 degrees. Much less than yours.
My stirrup bars need to be well back - forward stirrup bars (so common) put me into a bracing position that wants to force more ankle flexion than I can manage. Putting weight into my heels just shoves my leg forward which increases ankle flexion as I chase the stirrup. That’s a common enough issue with too forward stirrup bars, it just causes more issues when you physically can’t bend that way.
More anatomically correct stirrup bar placement + wide track flexible bed stirrups has almost eliminated the fiddling with my right leg and stirrup. I still have to focus on posture, but I’m no longer thinking about my leg the entire ride.