Unreferenced RMAs from Order Management creates a Single Credit Memo together?

Summary:

Unreferenced RMAs of a customer from Order Management when run through Import AutoInvoice program results in creating a Single Credit Memo for all those customer RMAs.
It is expected to create separate Credit Memos instead of a single credit memo.

Content (please ensure you mask any confidential information):

Root Cause:
1. No grouping rule is enabled for Credit Memo Transaction Class. It is defined for Invoice only, which is mapped to DOO Transaction Source.
2. By seeded functionality, every RMA requires its reference to Original Sales Order. Similarly, every Credit Memo requires its reference to Original Invoice. However, for Unreferenced RMA Sales Order Type, no invoice gets created in AR Billing. Hence the Credit Memo with no reference to Original Invoice is grouped to a single invoice.