Customer Payment Allocations

We import a large number of our customer invoices and payments into Sage 50.  This leaves the customer records with zero balances but all transactions unallocated.  It then can take hours each year manually allocating the entries when it should be a simple process of switching a payment flag.  Surely there should be a process where you can opt to flag all items where the account has a zero balance.

Is this something that can be introduced?