Logic in RSSP header level PO charge account generation

Summary:

In the "original" Purchase Requisition area, the requester was only updating the PO charge accounts line by line, but seems that in the new Responsive Self Service Procurement Application the requester can use also header level to update the PO charge account for all lines.

Content (please ensure you mask any confidential information):

Our customer has had specific requirement for investment numbers in PR's, and we are having separate "Investment" field, in the additional fields, which also affects to the PO charge account investment. This seems to work also in the new Responsive Self Service Procurement Application in LINE level, but it does not work correctly at all with the header level updates. Therefore, my question is, that should the header level PO charge account have similar kind of logic as the line level? As seems that it does not work currently. Or how we can make this described requirement work also in