The EFT Module is not required to process Direct Debit transactions if using RE version 7.93 Patch 10 or higher.
Direct Debit transactions can be processed with Blackbaud Merchant Service on 7.93 Patch 10 or higher directly from a gift batch.  The Gift type must be Cash and the Pay Method will be Direct Debit.  The Constituent record must have a Relationship on their Constituent record with a Financial Institution.