My back angle is 46 deg. Bar drop a modest 50 mm to the tops. Basically an endurance-minded fit. I've done this balance test many times and just find it too vague to define a specific position. I have quite a slim upper body and a fairly strong core, so maybe that's a factor? I had better results defining my setback based on how smoothly I pedal. My starting point was simply the middle of the saddle rail with the stock seatpost. My seatpost happens to have an offset flip-head so you can flip it over changing the post setback from 25 - 13 mm. I marginally prefer the 13 mm position with the saddle rails still centred. But it is not a big deal for me either way. When riding, my hands feel comfortable on long rides and the bike feels well balanced. I don't find myself edging forward or backward on the saddle, so I guess it's all good.