How to correct billing on ARM?

We have a client that gives a situation like this - sales order is already set up, revenue recognition is correct, and has been recognized partially at month end; instead of billing 2 year in front, it should be split to 2 invoices, 50/50 in year 1 and year 2.

In this situation, since the revenue is not changing, and they just need correction on the invoice, what i'm suggesting to the client is that to use a separate item Billing Correction that has Direct Revenue Posting checked on the item, so it does not go through the ARM module; and the income account can just be deferred revenue. So when we credit the full invoice, and reinvoice at 50% year 1 and 50% year 2, it only offsets the deferred revenue and does not touch the revenue side, since it's correct in the first place.