I have a client in the software industry implementing Advanced Projects with two requirements that are running into each other.  Hoping someone else has seen this in the past

Requirement 1 - CoA is structured to break professional services revenue into sub accounts based on type of work being completed (Project Services, Data Migration, Custom Development, Integration, etc)

Requirement 2 - Advanced Billing must be turned on to support billing fixed bid or milestone projects via Sales Order > Invoice.

Turning on Advanced Billing means selecting a single service item as the 'Billing Item' on the project record, which then severely limits the ability to break out services revenue from the project per the CoA as the billing item can only be mapped to a single revenue account.