On this stalk, the terminal flower has a double socket (the second is still a bud). Is it possible that the 2nd flower will be a 4x4x4 or is the first to bloom of a double socket usually the 4x4x4?? Also, is it typical for a ffo to revert back to a normal flower?

I would guess the 2nd flower in the terminal socket will have parts in 4s, but who knows? These types of traits are normally somewhat unpredictable. Usually, they do revert back to normal flowers, but I've heard Margie claim that the 4x4x4 trait is relatively stable in this plant.

Thank you for the information. I will be keeping a close eye on it as I am still hoping for a 4x4x4 ...

No luck - the 2nd bud in the socket bloomed and it's 3x3.