This is troublesome for built in shapes such as squares (since dialing the exact measurement in the toolbar will stretch the shape and skew the radius).
Two more things:
-Grid Array doesn’t support calculations.
-Grid Array shows (mm) even when Units / Grids is set to Inches (only cosmetic on the UI / the spacing is correctly made as inches).
Supporting calculations in the entry boxes means replacing the code that handles them, so it’ll take some time for me to convert things over. I’ll try to get the Shape Properties done before the next release. I’ve also made a note to correct the dimensions postfix on the grid array box. Thanks for reporting that.