For context: I am an ASA Sailing Instructor. Courses that I am certified to teach include ASA 118 - advanced docking.
The pivot point of a monohull sloop sailboat MOVES. When the boat is moving forward, the pivot point of a sloop is usually at the mast. When moving backward, the pivot point of a sloop moves aft (usually at or near the companionway).
I believe that it is best if the mid-ship cleat is aft of the CLR, but this is not vital. The location of the mid-ship cleat is less important than the fact that one is needed. On my O'day 35, I have a movable cleat from Garhauer, mounted all the way forward on my genoa track.
When I dock single handed, I tie up to a pier that is slightly longer than my boat. I bring the boat along the pier slowly, with fenders out, and toss a loop in a stern line which is doubled back to me, over a cleat/bollard on the pier as I approach. I use this line which is brought back to the stern cleat to stop the boat. Once stopped, I position the boat where I want it by engaging the transmission in forward at idle speed while turning the wheel into the pier. I go forward and toss a bow line to the pier, then hop off the boat at the shrouds so that I can secure the bow and then the boat.