Direct Ship - Is it safe to reverse receipt, then cancel an unwanted OD order, while leaving the rel

I wonder if you can advise on the following scenario, as I cannot find any documentation relating to anything similar.

An SD/OD was raised, then one line was cancelled and another replaced it, but the price was unchanged, so the supplier invoice matched.

Subsequently, the customer requested a replacement invoice in EUR instead of GBP, so the original SD was credited and a new SD raised with the correct EUR currency.

So far so good.

However, the problem is that the new SD generated a new OD that is not needed, as the transaction itself all took place and was completed under the original SD/OD transaction.