One of your ideas has been delivered from your suggestion.Credit Memo - Freight and Extra Costs Proration

Easily back out all the financial impact of the original invoice by creating a credit memo and specifying an amount for freight and extra cost on a credit memo invoice header. You can also choose to prorate the freight and extra cost to credit memo lines.

This allows you to credit back freight and extra cost when creating a credit memo.

Steps to Enable

You don't need to do anything to enable this feature.