No this is counter productive and not needed. You would be running in reverse. The created QEX file is a product of the plug in sending the PSCS6 finished file to Qimage for sizing, placement and printing. If there is something that needs repairing, redo the original raw file and resend a new QEX file to Qimage Delete the old one of course.
Photo Shop does not recognize the created QEX  file
Fred

PS I thought of a good analogy
You go to the hardware store to get a new key made for your front door.
You bring it home and decide you would rather have that key for the garage door.
You cannot bring that key back to the hardware store to be reworked.
He must start over.

Chuck,
It is even simpler than that.
You can always "Send to Photo Editor" from Qimage Ultimate any file that is normally accepted by PS.
A QEX file is a specialized file created from the gizzards of PSCS6 for one purpose; to be exported to Qimage.
You can still send PSD, TIF, JPG, etc in either direction by save as..... The plugin creates a qex image that is extremely high quality for printing with Qimage.

OK All good now.
Merry and Happy to all
Fred