Pan F stock would really be squirrely in sheet size. People put all kinds of things in sheet film holders, including thin lith film. But doing something
voluntarily is a little different game than offering a product with your name on it that you know won't be ideal from a mechanical standpoint.
Sheet films really need to be on some kind of stiff, dimensionally-stable stock of the correct thickness. Maybe this won't be a terrible issue with
this anticipated Double-XX product, but once you move up to 8x10, you quickly learn to adapt either adhesive or vaccuum holders or the film
with either potentially pop or just not hold focus due to not being flat. ... might not bother a contact printer who simply thinks an 8x10 is just
a cool oversized Holga, but it would drive the rest of us crazy. ... But there are things you can do to help the film from popping in even 4x5
holders, like acclimating your gear to the ambient working temperatures in winter before shooting it - just like you would with lenses to keep
them from fogging up, or by making your own adhesive holders. But the the problem is minor in 4x5 compared to even bigger formats.