Frustrating that something so straightforward as placing 2 5x7s across a 10 inch wide page doesn't work the way it should.
Sorry, but I had to quit for the day, and thankfully, Terry took over.
Here's some thing's: Check the print queue in Qimage and read out the print size to ascertain that Qimage is actually sending 5 x 7 to the driver.
Now read the printable area above the top right of the preview panel. I think you want to print 2 5 x7 with the two 5 inch sides together to 2 vertical images will fit on the 10" roll.
In order to do that, Qimage must report 10 inches or better or printable width on that roll paper. So 9.97 will not work.
In some drivers, there's a limit to how much we can cheat.
Using (as close as I can come) the driver for the 6100, I got the screen to show that it will and should work.
I set the page size to CUSTOM and then 10.02 x 15.00 Checkmark in borderless
That allows me to set 4 5 x 7s on that page, but most important, two 5 x 7s side by side.
See attached snaps.
The only thing I would have to print to experiment is the third screen snap; the one that offers you choices of whether to scale to fit or not.
I would try the upper dot with expansion on and off. Then the middle dot with expansion on and off.
One of those will work.
Give it a shot.