Dear Mr. book, Mr. Lonkar,
@ Mr. Lonkar, this is good thought out process however there is small complexity which is lets assume the customer wants to return the product for any reason via customer return.
Since the product is consumed, we don't have an option to undo consumption to return the product to enable a credit memo invoice request.
We cannot proceed with return without reference in this case as have already billed your customer for consumption.
Regards
Leo