Thanks guys, that was educational! I guess I was fixated on the upresing and sharpening features of the Print module, and completely forgot that the same engine (I hope) exists in the Export function.
Bart, thanks for the Difference tip. It was amazing to discover there is no difference between jpeg and tiff files whatsoever, in spite of the fact that one is 6-7 times larger in Mb than the other. How is that even possible? Could it be because of the screen resolution (94 ppi in my case), i.e., the screen not having enough resolution to show the difference, but the print at 300 ppi would?