How do I get this display to run at 1920x720 (native resolution)?

[Ninjanometry]

I purchased a 12.3" monitor to use as a secondary display for my Steam Deck. It is sold in multiple places under a few different brand names all claiming that its native resolution is 1920x720. I have also seen that this panel is used in BMW vehicles as the infotainment/dashboard display and the documentation for that use case also shows a 1920x720 native resolution. The problem is that I cannot get Windows, or Steam OS to run the display at that resolution. I'm guessing that Steam OS will be more of a challenge, (I could be wrong...). My research thus far has at best determined that the display controller PCB included in the monitor is somehow preventing the native resolution from being "offered" as an option to the OS of the computers I have connected it to. I have tried CRU (Custom Resolution Utility) and that hasn't worked, but I haven't gone so far as editing an INF file manually as that's a bit intimidating for now. The only resolutions that work are basically 16:9 and 4:3 aspect ratios such as 1080p or 800x600 but, at 1920x720, this display is much closer to a 21:9 aspect ratio which is one of the main reasons I selected it. I have only tried HDMI if that matters.
Can anyone help me get this thing to act right?

This is a stock photo of the display/monitor:

Links to the product pages on AliExpress (where I bought mine) and Amazon:
https://www.aliexpress.com/item/3256803925900560.html
https://www.amazon.com/VSDISPLAY-1920x720-VS123ZJ01A-12-3inch-Stretched/dp/B09STFLN9Z

The Amazon seller being EXTREMELY helpful when I tried to ask them about it :

And just for context, here's my admittedly ridiculous Steam Deck setup including the monitor in question:

 

[An0maly_76]

That resolution makes for a 2.667 aspect ratio, which nothing supports AFAIK.

[Ninjanometry]

23 hours ago, An0maly_76 said:

That resolution makes for a 2.667 aspect ratio, which nothing supports AFAIK.

I doubt that aspect ratio is a deciding factor for compatibility. The EDID just tells the OS what to do and it does it. There seems to be support for the resolution in the Raspberry Pi world.

[Ninjanometry]

Bumping for more potential help...