I have a widescreen display (57") configured as 2 4K displays side-by-side, driven by a M1 Max Macbook Pro. Uses two cables. Note: the M1 Max is not capable of driving the monitor as a single 8K2K display, so I have to drive it as two separate displays.

The widescreen is great for viewing landscape photographs, a hobby of mine. From time to time, I put a landscape picture I've taken as my wallpaper (split seamlessly between two displays). And I take a break from work and enjoy the photograph, hopefully by just clicking something, my wallpaper is visible nearly totally uncluttered (app windows and Desktop folders and drives out of the way). Anyway, I set Stage Manager up to do this. But it's a bit of a hack and not really one click. It also requires each Display to have its own separate Space, so I cannot have a window that spans the two sides in this mode. If I turn off this, and don't use Spaces, I can have one window that's way wider than one 4K display. To illustrate what I mean, I made a short video (3 mins).

YouTube State Manager hack (3 mins)

I just wonder if there is a better way to achieve what I want.

thanks!