I wouldn't let those spares go any longer. You don't know how long they were sitting at RD. Open try cryo and if they have an off smell give them a good rinse. If the smell is still there then I would get rid of them.
For briskets, I usually go 40 days past the pack date, but you have to know the pack date to go that long. The date codes at RD are the day that they print the price label and that could be a couple of days past the pack date or it could be longer.
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