How can I get Acrobat Reader DC to change its Page Units to mm, PERMANENTLY?

Hello

How can I get Adobe Acrobat Reader DC to default to the METRIC system (i.e. "mm") rather than defaulting to Inches?

Background

Every time I re-open Acrobat Reader I have to change the units (using: Edit ==> Preferences ==> Units ==> Page Units ==> "millimeters".  This is deeply irritating. I know of no other application that refuses to store settings like this!  [GRRRR]

J

PS I am running the latest versions of both Acrobat Reader DC and Windows 10. 
i.e. I am running Adobe Acrobat Reader DC version 2022.001.20085 (64-bit) on Windows 10 version 21H2 (OS Build 19044.115.86).