Rusty, I would see this as an off road only thing for having the drive line attached, low speed. That said, there may be advantage to having hydraulic, maybe air cylinders to help it stay in the desired position, especially when backing. I'm going to have the PTO on the tranny, so could do some hydraulic steering. I have a surplus of 2" x 24" double action cylinders. There could be a floating position, a valve with open center and a powered turn left and right by position of a valve. Hmmmm
Re the drive line, it's 5 1/2" off of center. If the radius of the ark that the trailer would turn hooked to the pintle is a chord across, it would need about 2x that distance of drive expansion and contraction or 10" of travel for a full turn to one side. The going the other way, it must collapse about the same amount. I could be wrong, but having 20" plus of travel seems problematic.
I would bring the drive line to the center of the pintle and then at the trailer, do the same thing going back to the left side (axle location). Theoretically a straight turn would result in no length changes. Add in a high trailer angle going up and down and to figure that members linear distance it must move...I don't think it will be long.
Quick connect could be the portions connected to the two axles. It would be nice to have lockouts on the trailer axles but removing the driveshafts would be simple and not cost $1000