EFC appeal - worth it?

On what basis would you appeal? Subsidized loans are federal loans, so colleges cannot make an exception to federal rules to allow you to receive a subsidized loan. If you reported the LLC the way FAFSA required, schools cannot adjust to remove it. If federal rules allowed ignoring that money, they would not have required it to be reported.

I understand how you feel. However, your efforts would be best spent looking for schools you can afford.