Once the sales return is saved but before submission, if any item is changed in the row, the incoming rate (costing) field is not refreshed while resaving and submitting.
Are you saying you want the updated rate of the items in the sales return?
What is the use case for this?
The cost rate is not getting refreshed if we change any item in the child table.
I think the server script is written on the event “Before Insert” or “After Insert” and therefore incoming rate [costing] is not getting refreshed.
Similarly, in the Sales Order also “item Tax Template” is not getting refreshed if we change any item having different Tax rates.