The use of "AVATAR" tag:
This appears to be a way of designating characters made or selected via character creation? The tag makes its way into the shared library via SelectAndStartDialog(), presumably for sorting out issues related to dialogs with Origin recruited characters. This tag also appears to be responsible for adding the little crown in the UI portrait for the character. Is this hard-coded? Could we change the tag to something else and still get the crown in the UI?
Unfortunately this is hardcoded and you'll need to use a different Tag. However remember that tags that appear in the character sheet are translated, so you can have a tag "MOD_AVATAR" and the translation for it is "Avatar". We never expose the tag "AVATAR" in game, so you shouldn't have to worry about visual duplication.
Regards,
Koala
