First the states have to tell Intuit that their software has been updated to accept a later payment date.  I think it involves more than an on/off switch at the state router.  Have you checked on what other software vendors are able to do?

I always wonder what people are doing with their money, that extra month.  Maybe it's reducing how much they owe on their credit cards, so they're getting a 1% or 2% yield.  Or maybe it's sitting in a money market account earning 0.25% annual rate.  Stock market?  It's at an all-time high, it's guaranteed to keep going higher, right?

Do enough returns with a payment date two months out, and you're going to have a client who dies or files bankruptcy before then.  I just prepare tax returns.  I don't cater to those needing cash-flow accommodation.