My experience is that not only are the panels generally worse, support for things like color calibration or Dolby Vision is almost impossible to find. Which is understandable because it's not obvious what advantage HDR would bring to digital signage.

While not HDR, I'd think colour calibration would be fairly important for signage.

If your company red is too washed out, or one section of a video-wall menu board is inconsistent brightness, it looks bad on your brand.

It depends. I have an Iiyama 44” and the display, while nominally 4K, is noticeably not as good as a good 32” 4K monitor. It’s not really visible when watching video, but using it as an external display looks horrible close up.

This is one of the ones with an android board in it, and if I did it again, I’d be getting someone sold as a computer monitor.

Of course a 44" panel doesn't look as good as a 32" one, it has lower pixel density. This has nothing to do with it having a bad panel.

The pixel density difference is about 30%. With careful close observation, you can easily see the pixels in each one. The monitor has smooth solid colors. The Iiyama looks more like it's a native 1920px wide with some 'interesting' pixel layouts for more dynamic range. It looks like complete crap with things like window titles, the MacOS blue highlight, and other gradients.