Hey, another Mike. 

There's no image editor in Qimage One so you can't apply DFS directly to images.  There is no way to really judge print sharpness via the monitor anyway so you really have to do test prints to get DFS the way you want it in prints.  That's the reason there is no "zoomable print preview" in QU: because to try to emulate print sharpness on a monitor is likely to throw you off since the two technologies are different.  It's always best to print some test photos to adjust DFS level in printing.  Once set, QU and Q1 will keep that level of sharpness for any size print given a photo of any resolution.

Regards,
Mike