Yes, but it's a bit tricky. I discovered this some time ago when I sent a DNG file to someone only to discover that my custom profile was not embedded in the file. All other adjustments to the raw were embedded, but not the profile.
When the other person opened the DNG on his system, the profile defaulted to Adobe Standard. Turns out that the DNG contained a "tag" for the custom profile, but not the profile itself. Since his system did not have that custom profile loaded, it defaulted to Adobe Standard. And no error message or other indication of the missing profile was displayed.
Here is what we learned:
In ACR, when you make changes (and just click Done) your DNG (or XMP) file is updated. In Lightroom, if you "Save Metadata" from the Library module the same thing happens. But in both cases, the profile "tag" is included and not the profile itself.
In ACR, if you "Save" a new DNG, that DNG will have the full profile embedded. In Lightroom if you Export a new DNG, that DNG will also have the full profile embedded. Those DNGs can be moved to another computer that does not have the profile and they will be OK.
Unfortunately, ACR does not allow you to overwrite the existing DNG when you do a save. ACR automatically generates a new file name to avoid duplicates. No way to avoid that. However, Lightroom does allow you to overwrite existing DNGs when you Export DNGs.
After I learned this I discovered I had some other trouble. I had deleted forever some custom profiles for an old camera I no longer owned. But I still had some raw files from that camera. When I checked them, they all had Adobe Standard as the profile (default). I was screwed, but fortunately those raw files were not very valuable.
