CSS marks property seems partialy supported
CSS crop property seems partialy supported :
marks: crop;
works ad intended : adds cropmarks and a margin to hold them, making the page larger and taller.
but
marks: none;
removes the cropmarks but leaves the margin, making the page larger and taller.
To fully remove the cropmarks and the white margin that holds them around the page, you need to remove / comment the whole CSS rule.