Thanks for the tip John! I actually did this without SwitchResX. Following James’ instructions, instead of creating a 2752x1152 option, in RDM 2.3.2, I created a 5120x2160 option and clicked the HiDPI checkbox. Once I restarted, I got an 2560x1071 HiDPI option in RDM! I don’t know why it was 1071 instead of 1080 height, but regardless it is full screen and WAY more sharp than just 2752x1152. So for anyone who doesn’t want to install SwitchResX, this is another option.