Wow, I didn't know this was even possible. It says the controls operate via DDC [1].

How do you know if your monitor, television, or project supports this? And does it depend on the connector used? (HDMI, DisplayPort, VGA?)

Does this work for most display peripherals, only newest/expensive ones, or something in between?

[1] https://en.wikipedia.org/wiki/Display_Data_Channel