There is but it is not in the UI. You have to edit the %LOCALAPPDATA%\Plex HTPC\plex.ini file and add:
[cec]
HDMIPort=####
(obviously changing #### to the correct port)
There is but it is not in the UI. You have to edit the %LOCALAPPDATA%\Plex HTPC\plex.ini file and add:
[cec]
HDMIPort=####
(obviously changing #### to the correct port)