Is there a way of turning child merge off for just address and not for additional ids?

Identical additional identifiers are getting retained even after the merge. Child merge is turned off. Our problem statement involves that identical additional identifiers are getting retained even after both the parties are merged. Whereas for other child entities like relationship, only one relationship is getting retained. Let us know the cause of this discrepancy. Also please let us know, if there is a way of turning child merge off for just address and not for additional identifiers.