Window Size - Red Line Appears While Dragging

If I have an OmniOutliner window that is zoomed to the max (not full screen), I see a red line when I drag the window to be a smaller size. Does the red line represent OO’s default window size? Is this customizable?

I never knew this existed which is pretty cool. I also love how it snaps when you are close to it.

That red line indicates a page boundary. It will only appear if you have disabled “Scale document to fit page width” in the File > Print panel:

You can change this setting without actually printing a document; clicking Cancel remember your changes but not actually send the document to the printer.

The Red line represents the page boundary but is there any way to to modify Page Setup. ?
I find printing to the right size page one of the most time consuming things to do in OmniOuliner

I want to be able to adjust the page size. It seems i either scale to fit the page or not. Trying to adjust the scale never seems to work as i think it should.

Would be good if it had something similar to to Excel printing.
For examplegive me options for scaling, number of pages wide, number of pages tall.