The difficulty is there is usually enough regulation in place to further nail you for _something_ if you get uppity. The objection letter I got noted two other minor violations - which had been present for quite some time, but nonetheless in violation. I’m sure they were cited ONLY to add “shut up and comply” weight to the other citation, even if it were not exactly “legal” on their part (to wit: “ok, you’re right and can leave that decoration up for another week - in the meantime, we’re filing a lien on your home for the other two just because we’re mad you challenged our authority”).
That wouldn't have happened on my watch. That is, I would never have used the tolerance for ongoing violations to coerce compliance with a different violation. The CC&Rs should be adequate for enforcement.
Some CC&Rs allow judgments on the part of the Board, either on a case-by-case basis or in adopting supporting regulations.
I would advise you to correct ALL violations of the CC&Rs. Violating them only makes you subject to arbitrary enforcement at a later time. You might be able to strengthen your case in front of a future Board if you get a letter from the present Board expressing their judgement that you are in compliance.
As for consequences, I would never expect to face anything beyond a warning for an initial infraction. Fines should be reserved for those who are deliberately flouting the legitimacy of the CC&Rs, to which the unit owner already agreed by purchasing a unit, or to cover actual damages caused by an infraction.