Just because your bundle has a BOC wrapper doesn't mean anything. First of all when going through sealed bricks the bundles are often gone through by a bricker and notes are pulled, shuffled, inserted, and sometimes "marked" etc, and then returned to the bank where they are counted and often given back out to customers if a bundle is requested. If you get a qty of bricks at any one time there are many occassions when the bundles you return may contain mutiple prefixes, consectutive runs, the odd note here and there especially if you are using a money counter machine your only concern is returning 100 notes per bundle.
As far as collecting info on replacements, only info from new sealed bricks is used no info from bundles are used because of what I described. Once a note has been confirmed it doesn't matter where you find it because then it is what it is...as for holding onto these notes is a crap shoot, but that is your call...
hope this helps