Comment 17 for bug 1975879

Yes, all copies regardless of a or b.

Discussion in CIG was that catalogers would most likely edit the owning library at the item level (where we would want the preference "change circ library" to be honored.

The discussion also was that when the cataloger chooses to edit at the call number level, they are probably transferring all copies to a different owning and circ library, regardless of whether they have indicated a preference for the circ library to change. (This also would take into account that the default for the preference is not to change the circ library. Since many catalogers might be unaware they need to check that box.)