How to create only the free units bucket without charging cycle forward fees?

The DOM is always 1 in our implementation. The Bill for a month for a customer is generated on any day during the first week of the month, based on the Bill Segment which the customer belongs to. For eg, a customer's bill belonging to a bill segment XX shall be (and should be) generated on every 5th of every month. However, OBRM demands creation of Free Counter buckets on the DOM for a customer for the upcoming month (to apply the rating-time free unit discounts for the usage CDRs) which can be achieved by triggering pin_cycle_forward utility. But