AutoAccounting Rules in AR – possible to override with Customer Class or Mapping Set?

Hello,

My client asked me to change the account distribution in AR transactions. Currently, AutoAccounting Rules for this Business Unit use the "Transaction Type" as the source to define the account distribution.

However, AutoAccounting Rules in AR only allow three possible sources: Transaction Type, Site, or Salesperson.

Is there any way to override this account with something like a Mapping Set? For example, in AR Transactions there is a field called "Customer Class". Can I configure something so that, regardless of the Transaction Type, the system uses the Customer Class to determine the account instead?

In other words, is it possible to set the logic so that: