Thought it was time to take photos. Sorry, I do not know how to put them in order with the text.
Here is a true thing of beauty. The center assembly loosely put together. Printed in eSun PLA+
I measured with my vernier to see the amount of deflection on the Z tubes and as you can see, almost a mm deflection of the arm.
Back view also shows how the arm deflects as it is not yet tightened down. This is the same deflection as with the Motor brackets.
The top view shows how robust the XY holes are, so no room for deflection here.