I can give you some insight here. I've been using a Samsung C49RG9x (49" ultra-wide) on Windows 10 for about four months. It was absolutely the right move to s

I can give you some insight here. I've been using a Samsung C49RG9x (49" ultra-wide) on Windows 10 for about four months. It was absolutely the right move to shift from 2 or 3 1080p monitors to a single 49" ultra-wide unit. Now I've switched back to using my 2020 13" MBP, and thus macOS, as my work horse. Long story short I had to use a previously bought "CalDigit Thunderbolt Station 3 Plus" (a dock, basically) to get the monitor to work correctly. This is because macOS cannot correctly render to the monitor over HDMI. I don't know why this is (because I don't really know much about displays or display protocols - I don't care to neither) but I tried a few cables and adapters and it gave me an odd resolution (3840x1080 I think) and a pink tint over the whole display. The CalDigit "dock" solved this as it exposes a Display Port (1.2) option to the Mac. The moment I plugged in the dock and then plugged the monitor into it via Display Port it worked flawlessly. That being said I still had to go into the display settings in macOS and change the resolution from "Default for display" to "Scaled". It's at that point you can choose the correct "5120x1440" native resolution for the monitor. I believe I'm getting a 120Hz refresh rate too. I've been extremely happy combining the ultra-wide with macOS and using Rectangle (which replaces FancyZones on Windows 10 for me) to "tile" windows all over the place. I hope this was helpful.