It's almost certain at this point that Leti will be over 300mm long, so only having a scanner that can do 210mm seems like a bit of a missed opportunity. Unlike A4, a handheld A3 document scanner basically doesn't exist. There are A3 all-in-one printers though, so I thought that I just had to surf though AliExpress and see if any particularly long looking CISs were used in A3 printers.

Within 10 minutes, I found this sensor that is used in: WF-7610 WF-7110 WF-7100 WF-7111 WF-7621 WF-7620. There's also another sensor that also includes WF-7710 WF-7720 L1455 and another for the WF-7715. I think they're all compatible with each other, but with subtle differences (and more expensive). This one is the most noticably different:

compared to

Still though, I wonder about the possible conflicts with using the T8-PRO N100 motherboard.