I'd much rather have "I am opting out of extra gifts" / "I am opting in to extra gifts." They are much clearer and use fewer negatives (the double-negatives get confusing and are easy to misread).
Those combined with the "You may ignore my Art/Fic preferences for extra gifts." / "You may ignore my Trick/Treat preferences for extra gifts." tags should be enough for people to understand when it's ok to deviate from the requests.
no subject
I'd much rather have "I am opting out of extra gifts" / "I am opting in to extra gifts." They are much clearer and use fewer negatives (the double-negatives get confusing and are easy to misread).
Those combined with the "You may ignore my Art/Fic preferences for extra gifts." / "You may ignore my Trick/Treat preferences for extra gifts." tags should be enough for people to understand when it's ok to deviate from the requests.