Welcome!

What you describe can be done by creating two layouts: one for portrait and one for landscape.  The executive summary is that you place one template on the page and then one floating text label on top.  Then you save that layout and repeat for the other orientation, saving a second layout for that one.

Here are the details.  Qimage can create a layout from any job so I would suggest doing the following.  First pick a portrait image and add it to your portrait page as you normally would.  Then add a floating text label and position it where you like over that print.  Now you have one print, I assume sized fit-to-page because you are doing borderless, and one text label on top.  Now with this one page setup, you can save that as a layout to use later: just drop down the print placement button under the live view and select "Save Current as Custom Layout".  Give it a name like "Borderless 8.5x11 (portrait)" and save.  Qimage will ask if you want to start using the layout: you don't have to do that now.  You could say No, remove all from the live view, start over and create your landscape layout and save in the same way you did above except on a landscape orientation page.

After doing the above you have two layouts, one named portrait and one landscape.  Qimage can also sort your thumbnails by portrait/landscape: see View, Thumb Sort, Presort by Orientation.  That way all your port/land thumbs will be grouped so you can easily print them all if you like.

To use the layouts: drop down that same print placement button and choose "Load Custom Layout" and pick the appropriate one (portrait or landscape).  Once the layout loads, you have a layout that contains one template and one text label.  Just click the + on each thumbnail to add and when thumbs are added to the live view, they will fill the layout.  Meaning... Click + on the first thumb and you have page 1 with the filename on it.  Click + on the second thumb you want to print and you get page 2 in the same layout.  And so on.  Since the layout is one print on one page, it just creates a new page in that layout for each thumbnail you choose to add.

Two final notes: when positioning the floating text, consider how long your path+filenames will be when placing the floating text.  If your folders/files have varying length names, you may want to give a little buffer to account for that.  When in doubt, Qimage can handle that too: in your floating text setup, you can choose to align the label to the left or right automatically.  Also, note that the layout won't show the text label until you add prints so when you first load the layout you may see a red template and the text might look like it is missing.  That's because there is no print on that page: templates don't have "filenames".  Once you add a print to the open template and fill that template with an image, the text label will show.

Regards,
Mike