Any thoughts on the LG DualUp [0]? It looks quite interesting for portrait mode work, but I've held off from purchasing due to the... unusual aspect ratio and the fact that it'd be rather difficult to use for watching video content.

[0]: https://www.lg.com/uk/monitors/lg-28mq780-b

It looks really interesting! I found using a different aspect ratio (5:4 in my recent case) changes how I view and interact with the computer. It just feels refreshing to use something different after years of 16:9 and 16:10. Your window layout might be different, which may or may not benefit your workflow.

I agree video content might look a little strange unless it was kept on either the top or bottom, and not full screened.

I can't imagine it makes the most sense unless you got two of them side-by-side--though that would depend on the nature of your work. I use a 43" 4k 16:9 monitor and don't use the full height, leaving part of the top and bottom edges empty. Moving your eyes/head that much vertically just doesn't seem very natural or ergonomic.