Hello,

Do you think this is correct?
Try to do this weird exercise for 150 line order and you'll understand that is impossible to complete in reasonable time frame.

From the other hand, what is the accounting software for?
I think this issue must be corrected as follows:

1. Miscellaneous charges should be processed in selected vendor currency.
2. Separate field for manual proration must be added below the existing "Allocated Misc.".
3. Running total for manually prorated amount should be shown.

Please let me know if you think it is unreasonable or you have any other solution in mind. Because the current workaround you offered won't be in use until this process is corrected.

Regards
Victor