NetSuite Revenue Recognition - all previously billed, revenue still to recognise

Hi fellow Guru's,

I appreciate this is a complex subject but I really would appreciate any comments / thoughts on the following. We are importing sales orders containing items that have revenue recognition schedules associated with them. We have many examples where the client has been billed but there is still revenue to recognise. NetSuite seems to insist that there is some sort of billing schedule on the SO - other sources are recommending creating a prior period dummy invoice and then a complex reversal process using return authorisations transitioned to credit memo's and linked journal entries to the dummy invoice and credit