No software can control how much the roll advances before or after a job since that is internal to the driver.  But... you can control how much leftover space is on your "page".  All printers require that you define a page length when using roll paper so just be sure there is no white space above or below the print on Qimage's live view.  If there is white space either above or below the print, your page length is longer than it needs to be.  The solution is to redefine your page length to something smaller.  Qimage will do that for you automatically if you change your placement to IntelliCut and you turn on the auto roll length option next to the media size dropdown.

Regards,
Mike