Currently if the same one SKU is set on two different bundles, you cannot complete a return for the items in one go as you receive the error "Could not add return item cannot return more stock than is remaining the order." You then have complete the return multiple times in parts.
I've been advised , If both bundle rows resolve to the same order-item id (or the same child product is counted against a single line), the second row's already-returned quantity is double-counted and legitimately-returnable stock shows as 0.
This means the client is over charged for the return and would need to be manually adjusted.
