You might be able to get away with just about anything for a while and maybe for a while longer even after you get caught, once. The not so nice people that run the airline (particularly flight operations), however will endeavor to make your life a living hell if your actions are out of bounds as defined by the contract. They live for that and they are good at it.

You'd also really be asking a lot of the rest of us - paying union dues to an organization that has very little interest in grieving much - to support your actions if you willfully choose to violate the terms of employment or the CBA. If you don't want to work under the conditions the junior reserves are subject to (I sure as heck wouldn't) either stay where you are until we change it, or get hired here with the primary intent of making waves until they fire you. I'd buy you a beer in either case.