I know this question was asked a year and 2 months ago, but I just saw it, and I see it has never been answered.
So in case someone else wants a FREE tool to do the same thing, i.e. print a PDF at a zoomed setting to fill the page (like manuals for a product you own that are printed in tiny text in a little rectangle in the centre of an A4 page)..
It should be in your repo. I am using xreader 2.4.4 in Mint 19.9.
File > Print > General lets you choose which Printer, which Pages to print, Number of copies etc,
From General tab, opening the page Setup tab lets you choose:
Single or Two Sided printing (if you printer supports Duplex)
and some other settings.
At the Bottom of the list is Scale. In most cases around 200% works well on those little manuals.
To the RIGHT is a Preview button so you can see if you made the right scale (zoom) choice.
Hope this helps.