Disabling "Augmented Profiles"

Whenever I play to my Chromecast I used to have it set to ALWAYS convert to AC3. This worked amazingly well until the advent of "Augmented Profiles".

Since Augmented Profiles became a thing, the Chromecast seems to tell my server that it can handle EAC3 and completely overwrites the Chromecast.xml profile that I had carefully created. This means I hear precisely nothing because my speakers cannot handle EAC3. How the hell can I tell plex to convert the audio? It shouldn't be rocket science!