These are always fun to see. Thanks for sharing them.
The Horst welding version is pretty complex, perhaps too complex. I would worry that in its current version that it isn't all that tolerant of dirt/gravel. Personally, I like to see designs wherein the act of coupling locks the hydraulics as its last step. i.e. Last to open, first to close.
I know an inventor who had a variation on the EngCon quick hitch. He had designed it for his own farm equipment, exploiting the fact that on the Q/A plate, when the attachment is picked up, the location of the the couplers is known pretty accurately. His Q/A system was a little more triangular, enabling a slightly larger travel of the Q/A plate relative to the attachment prior to engagement, facilitating the last to open, first to close system.
He then used solenoids to multiplex the single hydraulic flow into multiple circuits. To be honest, I don't think he had a design that would have been compatible with a PTO and additional circuits, but it worked well for him. Then again, to be fair my memory isn't what it used to be.
There was talk that JD was going to distribute it in Europe, but I don't know what happened.
When I looked at the US market, it turned out that there are a bunch of these designs out there (in terms of patents), but not so many devices. I think the EngCon video illustrates the utility of the these systems to operators that need multiple implements in short order.
For the PT, you could make one, provided that you either trimmed up the Q/A plates and receivers for a higher precision fit, or used flat face couplers in a spring loaded block to allow for the movement in the plates.
Of course, this brings us back to MossRoads' comment,
"I wonder how much that costs?"
Thanks for sharing the link to video JJ. It is pretty slick.
All the best,
Peter