The smallest distance for the crop area boundary is 3 mm. This leads to overlaps with the sheet in normal plan layouts which have to manually be corrected for each sheet and every grid line individually. The image below illustrates how many times (>50x) that would be necessary for only one of our plans – of which we actually have 80 in this project (10 stories in the building, each with 8 sectors).
Either this is a lot of work or you do as we did it: Create a grid out of annotation lines which crop just fine. The much more elegant solution would of course be to allow the crop area boundary to be 0 mm or to make grid lines crop like annotation lines.