When I installed my rear disc brakes I added a Wilwood adjustable proportioning valve in the rear line in front of the rear tire mounted on the frame with the knob facing the ground, you can't see it but it is super accessible to adjust.
I personally would not buy one where the knob is on the valve you will be stuck mounting it where you can get to it to adjust it and that will definitely keep you from putting it in the stock location.
I personally would not buy one where the knob is on the valve you will be stuck mounting it where you can get to it to adjust it and that will definitely keep you from putting it in the stock location.