And we've had the request denied.
So what. If we have some wins and have some losses, that’s different than the “all losses” idea you proposed in Post #2.
There is more to this than cases and code sections. There is the human/IRS administrative element. That’s the point you’re missing. If IRS refuses to go along with you, you will not win in court, which is pretty much all of your citations are telling us. I agree with that. But that’s only if you get denied first. Obviously, the IRS wouldn’t have an IRM Section on this issue if changing one’s election was impossible.
And I’m already familiar with what 6513(d) says. I get it that an overpayment, once credited, is no longer an overpayment (that can be refunded). You see the same thing in 301.6402-3.