given that there are charges from many DL FAs that they didn't ever sign a card but the IAM gave indications that it held cards in their name, you can bet the NMB is moving very carefully.
further, this is probably the largest card drive in the NMB's history. I'd be happy to hear what others they have presided over that were larger than 12K but I can't imagine there were many.
and yes, getting it right is the right thing to do regardless of how long it takes.
it is also noteworthy that DL has said virtually nothing and hasn't made any moves to change compensation issues since the insurance redo so it is possible that DL knows the list of FAs that say they didn't sign a card but the IAM indicated they had one for them is larger than some people might want to admit.