it embeds custom DNG profile if that profile is referenced in a sidecar xmp file at the moment of conversion
OK so if I have this correct:
You open the camera raw (which of course that converter understands).
You set say ACR for a custom DNG camera profile (since DNG profiles work with non DNG raws thankfully).
THEN you convert to DNG, that newer DNG camera profile is embedded. Of course that makes perfect sense, any other behavior would be a bad idea.
And of course lots of other data that was previously stored in a sidecar is now embedded in the DNG.