I have made some tests before in a conventional racket and the friction of the frame and strings make a big difference but I don't think you understand my question. The direction of the tensioner is always away from the pivot point of the turntable. If you use a brake you will need to turn the racket so that the cross string is perpendicular to the to the center line of the racket and in line with the bottom of the O Port which creates an angle going into the tensioners gripper. That angle will vary depending on which cross string you are tensioning and how far the cross string is from the center line. If the cross string were far enough it so that the string were perpendicular to the line of pull there would be 0 lbs of tension on the string.
When you are tensioning a cross string in a Prince racket (in an O Port) the string always exits the frame in the bottom of the port and when you are string the top half of the racket that port is between the racket and the tensioner so the string naturally wants to pull to the top of the O port. Putting a spacer like a boomerranf or sharpie cap hold the string in the bottom of the port. Or you could use an S hook to connect the string to a lower port which hold it down.
When using a brake the far side of the racket holds one end of the string which goes straight to the gripper in the tensioner and enters that gripper at on angle and that angle varies depending on how far the cross is the the pivot point. The turntable is then locked with a brake to hold e string in the lower part of the port. What I am having trouble understanding is how pulling in one direction enables you to put the same tension on every string because of the different angles of the string.
I would like to apologize to anyone I have not offended. Please be patient I will get to you shortly.