@wemarch Not on a raspberry pi, I used one a few years ago when setting up a cctv security system for a local business. But it SHOULD work (assuming you can find one with hdmi outs) since it doesn’t take any kind of drivers, it just reports a 2560x720 (2 identical 1280x720 monitors in the case of the cctv setup I put together) sized monitor to the video chipset.

The question is, can the video core of a Raspberry Pi handle an ultrawide display?

There’s always an outside solution (though you would need a separate power supply). Basically a box that takes two monitors and plugs into one port on the Pi (and the pi thinks it sees one superwide monitor).

Here is such a thing from Amazon (for DisplayPort, but I am sure HDMI adapters or a box for hdmi exists):
https://www.amazon.co.uk/Matrox-DualHead2Go-Digital-Display-Support/dp/B0080K6WIG