Loading 8.5x11 clear film in an Epson 7880

We’re wandering down the road of alternative processes and digital negatives. I’ve just (yesterday) taken delivery of a refurb 7880, to make some negs for a cyanotype course this weekend.
Currently testing using PermaJet Digital transfer film, using ultra chrome inks, while waiting for a few boxes of Pictorico Ultra Premium OHP Transparency Film, and a Cone Digital negative inkset to clear customs.

The 7880 refuses cut sheets (A4 - 210x297mm) of clear(ish) film, unless I disable the auto paper size/skew settings. Then It loads beautifully, But about 2" further down the film, than it should. I’ve tried loading the film with a sheet of copier paper behind (as I’ve done in the Canon 8400), but given the curl of the film, the vacuum doesn’t hold it flat (holds the copier paper), and leads to head strikes. Am I missing an obvious trick, or am I destined to tape each sheet of film to a carrier, prior to hitting print?

The 7880 is way easier to load sheets than the 8400, and I suspect has a subtly finer dither (and should be noticably better once we get the cone inks and QTR running), but if I can’t load the media, I’ll go plan B in the short term.

Any timely suggestions on how to load the film would be greatly appreciated.

Pictorico film arrived today from B&H (ordered Monday), and happily, the 7880 can see the very slightly milky base of the film just fine. So, in trying to prepare myself for the process, using the Permajet, I ended up causing myself more problems than needed.
I did have success printing onto the Permajet, by decurling the film around a 3" tube, taped between smooth copier paper - the film lost its curl for long enough to load and run A4. 20 minutes later, the curl is back, but not an issue after it’s printed.

Also, Cone Piezography inks arrived (again ordered Monday). Letting them warm up, before going down the rabbit hole.