You are correct. When I disabled the sound receiver the Sony couldn't play movies with DTS.
Could it be possible to recognize this on the server side? (I don't know if the device is transmitting its capabilities?).
Another possible solution would be to have the ability to couple a profile to a device (in the devices menu). That way a user can create a specific profile for a specific device.
I know it's currently possible using the FriendlyName Regex... but allowing this from the GUI would be awesome (just copy the profile with a new specific FriendlyName).
You could even ship profiles out-of-the-box that are disabled by default, and are only enabled when connected to a specific device. This would allow for a better fine-tuning of all the devices.
Looking at the code this shouldn't be a large thing to build into the backend.... I don't know how much work this is on the front-end? (not really a front-end guy )