Newer Macs (M3 MBPs with HDMI port and possibly the upcoming M4 macs) have working HDMI-CEC hardware and are enabled and accessible in newer macOS versions.

It might be useful to add a simple volume up/down HDMI-CEC control feature to the app and give the option to tie it to the volume up/down keyboard.

Standby control is already implemented natively in macOS for these devices (the connected TV and connected receivers can be put to standby mode and powered on display sleep if HDMI-CEC control is enabled) - so no need to add that feature.