I am trying to run an LG Ultrawide 5k2k screen on a brand new Apple M1 MacMini (Apple Silicon). This basically works fine. The display gets recognized as what it is and 5120x2160px is used as native resolution. The issue is with UI scaling. The highest scaling is native resolution on this display which is nearly unusable (way too small). The second step already uses the infamous 3008x12xx (don't remember the exact height now). While kind of usable the UI is very big already at that scale. The scaling factor is close to 0.6 already at this stage - every other scaling option is again bigger (comically big up to macOS asking if I really want to use the bigger ones when I click them). RDM - https://github.com/avibrazil/RDM is a little tool that thankfully gives me a full range of available resolutions which Apple seems to want to protect me from but that doesn't really help. The 3008x12xx is the highest available HiDPI resolution that apple provides for whatever reason. Now SwitchResX is a classical solution to all resolution problem for over a decade now (as Apple always sucked at resolution things in macOS). Unfortunately Apple seems to have locked down all custom resolution stuff for BigSur on Apple Silicon. I still need to test on my old iMac if this would be a solution but for the Apple Silicon mac it currently isn't. No custom resolution is possible. Apple has removed all capabilities to customise any resolution or monitor setting. If Apple doesn't change this or provide again monitors customisation features in macOS, ten this is definitely gone. To be clear: What still works is using tools like RDM to select any resolution that is basically there but not visible and selectable through the macOS Display Settings PrefPane. What won't work anymore is customizing the resolution used for your display. This was often needed when macOS wasn't able to detect the right resolution with your display or if you needed to use overscan. Also for custom HiDPI-Resolutions (UI Scaling) there seems to be no other way than a custom resolution. I'm thankful for any tip on how to solve the issue or how to bring this to Apple's attention. The display I'm using is a modern, Thunderbolt 3 display from Apple's display partner LG. It offers quite a good quality and works great from plugging in. Due to scaling it's not really great to work with and I'm probably going to send it back. This cuts down the possible options for an external HiDPI monitor to very few of which one at least is insanely expensive and would cost more than 3 times the money than the spec'd out MacMini.