We were wondering why the automated payment proposal function is available for vendors but not for customers. Since the implementation for vendors exists, we thought we would simply build the automation for customers ourselves. Unfortunately, the required base classes such as CustVendPaymProposalAutomationController are all internal so we can't inherit from them in our own module. To recreate the functionality, we would now have to copy all the base classes (CustVendPaymProposalAutomation...). My suggestion would be to make the automated payment proposal also available for customers or to open the corresponding base classes for inheritance.