I wouldn't classify Ultramodern5 as a setting; at least not the original edition I own. It's more of a toolkit that's targeted at a variety of modern to far future genres, but IMO not a particularly good one. This is what U5 states at the beginning of the Adventuring chapter.
"Ultramodern5 supports multiple styles of gaming, from long-running campaigns to fast run-and-gun missions, and can service just about any modern or sci-fi genre from high-stakes espionage to the zombie apocalypse."
The U5 book takes such a kitchen-sink-with-everything-tossed-in approach, that it's hard to discern what it's targetting or embracing. For instance, instead of detailing adventuring aspects like hazards, environment, terrain and travel, its Adventuring chapter is instead a series of references to encounter maps complete with corresponding, numbered descriptions such as you'd find in any adventure. The book includes a number of 8x10 gridded tiles, a few encounter maps and 1 map of Bagdad, but for scale they're far more granular than what you'd expect for a setting. It includes 3 adventures, but their background is minimal to the point that I find them a bit too brief for even an adventure.
If the U5 book is browsed quickly, I could see someone mistaking it as having some semblance of a setting. Dias Ex Machina Game's Amethyst and Apex which are available for 5e among other TTRPGs, are much more akin to settings.
