If this means, that on M1 Macs is not possible anymore to create Custom Resolutions (HiDPi) using SwitchResX, this should affect quite a lot of users. It seems that this tool was the only way to create your own HiDPi resolutions. On your monitor, you may want to use a horizontal resolution of at least 3200 points, which should be still plenty sharp and give you more space. I also had an eye on the LG Ultrafine 5k2k, but with this change to M1 Macs / MacOS 11 (Arm), I would also think twice before accepting to work on a 3008 points horizontal resolution. SwitchResX was always a workaround to create resolutions that do work great, but are not supported by MacOS by default. There should be at least an option in Monitor settings to create and use any point resolution that meets the aspect ratio of the monitor (and is smaller than the native resolution of the panel). Unfortunately this is an area in MacOS, were we didn't see any improvements since the 2012 Retina MacbookPro, so don't get your hopes up that apple will solve this any time soon (if ever).