Hi Gail - I had not read far enough into your response after you explained Virginia, so I apologize for that. Had I read far enough I would not have responded to the OP. However, NJ instructions under page 1, Filing Status, it clearly states they are bound by whatever status they choose on their Federal return. You refer to page 15 which allows them to choose. In case of a conflict, fact-specific instructions usually trump general instructions, so I would say your answer would be more correct than mine.
However, yet another consideration (and I'm not going to spend the time to research) is whether NJ or VA requires a marriage of total income to the federal return regardless of filing status for state purposes. Essentially, many states do this in order to move the taxpayer into a higher bracket. Works like this: Spouse 1(VA) reports $70,000, Spouse 2(NJ) reports $30,000. States who do this would require reporting of $100,000 as total income to determine the progressive tax bracket and establish tax before proportionate reduction. For such an example, NJ would calculate tax on $100,000 based on filing status, then take 30% of the tax to assess the proper amount. This method will result in a higher NJ tax than simply taxing $30,000. The methodology requires tracking to the Federal return - meaning if there is a separate federal return $30,000 is reported to NJ, and if there is a MFJ return $100,000 is reported for NJ regardless of NJ filing status.
Following through on all options is what I do and it does run into time and fees. Although my state has no income tax, I have Federal contractors as customers who must file in every state where they have a contract. And being long and narrow with all contiguous states having an income tax, in Tennessee you're never far away from a client who has to deal with state income taxes.
Apologies to you, Gail, for not having read your entire message.