Your probably the only one that might be able to figure this out. Way back when I was able to search for someone who actually managed to get the PEN to work under Linuz with WINE. i haven;t set-up Wine yet, so this is just to get you to think about how. Thanks in advance.
So, they managed to use WINE, but got the output of the scanner to Linux windows. Have any ideas? Absolutely no hurry. it will take me a while to get WINW to work anyway.
there are also android and mac versions of their software, which are both very linux-like operating systems... also, have you tried simply connecting the irispen and treating it like a scanner?
Want to keep using your Plustek IRIScan 2 on macOS Sonoma, Windows 10, and more? VueScan has a built in Plustek Scanner Driver - so it works even without a driver.
www.hamrick.com
[edit]
I see it says "Irispen 2" in that web page, so You need to test this against your irispen.
since the device is a scanner, linux may already contain a driver for it, and there are easily installable linux scanner programs available in the Raspbian repositories. installing WINE or a VM may not be the best choice on a Pi Zero because of limited system resources...
the problems running WINE on a pi zero, are:
1) WINE is made for running x86 based software, and a pi zero uses an ARM processor, so a conversion/compatibility layer must be added first, such as QEMU.
2) the recommended memory for such a setup requires at least 1GB RAM, and the pi zero only has 512MB RAM for a standard pi4 with 4GB RAM (using a 2/2 split between system ram and video ram) setting this up isn't a problem, but on the pi zero it is a big problem.
this is why i recommended using a native linux scanning app instead, it's simple to install on a pi zero. if the OP tries this route, there are two excellent resources out there https://linuxquestions.org and https://www.raspberrypi.org/forums/ in case he has problems or questions.
Way back when I remember doing a search and someone did manage to get the IRISpen to work under linux. I can;t find that info now.
I may have written down the blurb.
Wondering: What about socat or ser2net?
e.g. The Windows input from the scanner which is USB might be able to be processed in Wine, but returned to the stty?
I guess it would be somewhat of an "OR" thing, where input either is from the active window or the scanner. Like having 2 keybpards.
The problem is not the physical data interface to access the raw data. It's the conversion of that data to something that Linux can use with the libsane API. That's the driver issue, a protocol driver is needed.