Actually, there are a lot of other options to ensure good faith bargaining. You can build in deadlines into the duration section of the agreement. You can include early openers for groups of sections rather than waiting for the full Section 6 opener. You can include automatic pay bumps every year past the amendable date. The list goes on.
Clinging to the hope of full retro pay is no way to force a company to bargain in good faith, because quite frankly, companies don't have enough cash laying around to pay full retro pay. This isn't 1999 anymore, folks. If you wait around for full retro, you're the only one that's going to get screwed, not the company, because they're never going to end up paying it. Think outside of the box to find ways to force them to bargain in good faith.
Don't worry anybody...the CEO is still getting his bonus and stock options.