Amazon.com: XEYOU HDMI Dummy Plug Display Emulator for Headless PC 4096x2160@60Hz, 3 Pack 4K Virtual Screen : Electronics
Software HDMI dummy - Allows custom scaled retina (HiDPI) resolutions on Apple Silicon/Intel Macs, Monterey compatible (more info in the comments) : r/apple
HDMI-Compatible Virtual Display Emulator 4K HD DDC EDID Dummy Plug Dongle - Robu.in | Indian Online Store | RC Hobby | Robotics
hdmi dummy plug, unboxed...for crypto or vfio - YouTube