If the Press Sheet is defined in inches (e.g., Letter (8.5 X 11 in)), the offsets in the layout tab will be defined in inches.
@pmaze wrote: My Waffle House
In imposition window, if you use preset format or custom size, even if you set the FFCore Region to "mm", settings apperas in inch.
Tested with french and english (US) language.
I appreciate the information and advice you have shared. I will try to figure it out for more.