The problem is the FAA completly caved on the rule after some pressure. Originally the extension was only for "unforeseen circumstances" beyond control and mutually agreed upon. Well that quickly came to be defined as anything that was not in the crews schedule as originally published is "unforeseen".
Just call fatigued if your not feeling safe, you might get paid you might not. The Feds see this as a company/Union issue and are not getting involved in repercussions of refusing an extension.