Seems like CEC still isn't supported. Would be very nice to have this for digital signage.
For current users, we do have a decent workaround. Emteria DOES work with our IRUSB device. You can use this little USB IR transceiver to automatically turn on and off TVs.
Docs on how to use with emteria at https://splash-tiles.com/help/emteria_setup.php
Note those docs say you can use SplashTiles to control IRUSB. You can actually control IRUSB directly via IP on port 9093.