Derive distribution string for Freight and Misc based on PO Inventory

Summary:

Our team is looking for the most efficient way to accommodate accounting for freight.

Content (please ensure you mask any confidential information):

Currently, invoices coming into Oracle from IDR are marking Freight and Misc lines are Prorate Across All Item Lines. This is fine when matched to a PO with item type of Expense. However, for PO matched with type of Inventory, we have a requirement for Freight and Misc to be booked to specific account string. Attempted to create SLA rule but Prorate seems to override SLA rule.

Is it possible to create SLA rule for this? Is there another solution other than creating manual journals to reclass?