Is this possible at the moment? I’m guessing not as we can’t get the screen res yet 
Can this option be added to the Popup action?
What happens when you leave all parameters set to ‘auto’? In my projects, the popup opens centered with this setting.
Ah, setting to ‘Exact’ position with default Auto’s in all of the position fields opens it at the centre. I should have tried that before posting Not very intuitive though!
Cheers!