Ciao DougIf I can permit me to suggest
When you finished the Pick & Place Machine plus the Feeding Machine
I think it will be useful you arrange your Pick & Place Machine Board "Bed" with an Under Plate (Bottom Plate) with installed a whole set of Pointy Tools (number corresponding to the max number of turret holes you can have in a board)
and
a Counter Board with a whole set of Hole Tools (number corresponding to the max number of turret holes you can have in a board) to be placed on the Top of the Pick & Place Machine Board "Bed" (and bloked in some way, like Threaded Rod that engases holes on the perifery of the Hole Tools Board or other way you think will perform better)

The Under Plate (Bottom Plate) will be moved UP (and down) with a small Hydraulic Piston (or perhaps Pneumatic Piston)
Something like this
Hidraulic


Pneumatic

This way you'll be able to lock (block) all the Turrets present on the board at the same time
Alternatively, to avoid secondary problems (how to leave spikes marks on places where there are no turrets), may be you must mount on the Under Plate (Bottom Plate) only the Pointy Tools corresponding to the Turrets placed for the specific Board you are building
I hope I explained what I mean in a comprehnsible way
Franco