mat2 changes the page format of the PDFs

When using mat2 non-lightweight, A4 becomes the american paper size. Therefore, every time the person I send it to goes to the printer they have to manually set the size to A4, which changes the output a little; or they just cannot print! On the other hand I rather not use lightweight because I rather do full sanitisation. It shouldn't be very hard to keep the same paper size, or to add an option to instruct mat2 about the paper size...

This would be greatly appreciated.