I couldn't figure out how the draft control worked when I first got my tractor, till I realized it was locked out! The manual was a bit confusing.
The flip lever 'bypasses' the draft control
the other linkage is what actually controls the draft control.
Basically, if you dont want to use the draft control for a 3pt implement, put the flip lever in place. Otherwise, the toplink pulls on the other linkage and will lift your implement based on where the draft control lever is set. It is mostly for ground engaging attachments like a plow.
I think the metal rod ends up pointing straight up. Basically when you flip it into place, it prevents the toplink from activating the 'sense linkage' for the draft control.
TSO's first picture shows it 'in place' for no draft control function.
Basically the draft control senses how hard something like a plow is pulling. And will lift it up out of the ground when you hit something like a rock. the control lever next to your 3pt lift control, will set how quickly it responds.
I think I'm tracking with you. I've tried to figure out the draft function, but had no idea it was locked out!