I wonder if there is some way to fashion the quick release by leaving the nut & splines in place, but cutting the wiper arm itself. Making some kind of sleeve arrangement to slide it on & off the "stub" (and then lock it with a cotter/lynch pin)....
With two of these, one on each side of the arm, maybe could cannibalize hinges & hinge pins for the purpose...
Just thinking out loud.
And yes, I realize more thought is going into this than it's worth.