I bought a MacStudio 2 months ago, on Sequoia you go to "display" and should see the various resolutions. If not, "advanced">"show resolutions as a list">"show all resolutions".
Unfortunately, resolutions offered were weird. Native is 5120x2160 but that wasn't offered and scaled resolutions were weird. I guess macOS didn't read monitor's information properly or something. I wasted a few hours frantically trying to figure out how to connect a $12k computer to a 4-year old monitor which should have been a breeze but for some reason wasn't. The same monitor worked fine on Linux or Windows.
Unfortunately, resolutions offered were weird. Native is 5120x2160 but that wasn't offered and scaled resolutions were weird. I guess macOS didn't read monitor's information properly or something. I wasted a few hours frantically trying to figure out how to connect a $12k computer to a 4-year old monitor which should have been a breeze but for some reason wasn't. The same monitor worked fine on Linux or Windows.