I don't want to use this connection point unless I can guarantee acceptable clearance.  I think I can grind/dremel it to be certain.  I don't want to scratch the cylinder.  Right now, it looks to be almost exactly in contact with the rockshaft at full extension (.0015 was the thinnest gap test I had). 

I can find no reference in the documentation to use of this connection point (I do show a picture of a dotted line to a pin insertion there, but not clearly related to anything else).  

Obviously there is a hole there for a reason.  But it is too close to the fender/rockshaft mount to get a normal pin in without catching on the mount.  It doesn't appear possible to insert a pin from the outside (that's long enough) due to the mount being in the way.  You can insert a pin from the inside (PTO shaft side), but there's only about 1/4" clearance with the mount, barely enough to cleanly put a clip through the end of the pin.  I can probably cut one of those multi-hole pins off at just the right length and grind it to minimum.  I'll have to guarantee no slop in the pin movement.

"The hole"...looks almost perfectly positioned for my desired usage (if I can successfully clear the rockshaft).

Ah, yes.  Makes perfect sense.  I should have known that.  Still, I need a solution to limit the operational range.  I've manually operated it in that position and it seems like it will work ok if I can guarantee clearance with the rockshaft when fully extended.