Does anybody have experience with "Balance forward billing" and Tax regulations in EU countries

I am  working at a EU client that has questions on AR I do not have a simple answer on, I hope one of you can help?

The client has Multiple billing systems all sending billing information to AR, they creat  AR transactions,  determines tax, print invoices, there will be complex revenue recognition on these AR-Transactions.

The client has"billing in advance" and billing in arrear

The whole receivable and collection features are not the issue at this point. Presenting the invoice and getting the revenue recognition correct is.

Because of different billing systems and different revenue recocnition complexity client want to create different AR transaction, but only present one Invoice  to the customer