Quick q: I have a 2-4-1 and GUF2. Should I achieve GGL, would it be plausible to use joker and both those vouchers for an F redemption booking, even if there's no Avios availability? Does it depend on a fare code existing within said cabin, or is any code (subject to availability) usable?

This would be the main reason for me to push to GGL, so want to make sure I'm not imagining the above.

Thanks