The problem is in the email body, not the subject.
If the settings for the "email subject showing" have "hub name" off and "camera name" on, the BODY of the email shows 'Camera "<hub name>"', when it should show 'Camera "Gate"'. (In my examples, "Gate" is the camera name.)
But, oddly enough if I turn on "hub name" for the email SUBJECT, the BODY of the email shows 'Camera "Gate"' properly.
If I turn off both "hub name" and "camera name" in the "email subject" configuration, the email body shows 'Camera "<hub name>/Gate"'.
It's almost as if it was designed to not duplicate data between the subject and body but was just implemented in a broken way, and should, in my opinion, instead include all the data in the body regardless of the subject settings. Perhaps in the body, 'Hub "<hub name>" Camera "Gate" saw a car in region "Tires" arriving at 13:11:47' instead of 'Camera "Gate" saw...', no matter the subject settings.
Also, the API doesn't show regions or modifiers, which would be great to have for feeding into outside automation. The modifiers (ie vehicles arriving/moving/departing, tires, steps, loitering) are an excellent feature - I use them extensively and would like to integrate them into my automation.