Does Book of Mormon Historicity Matter to Menu Mormons?

I once went to lunch with a self proclaimed “Menu Mormon” friend of mine. For those that don’t know that term, a “Menu Mormon” is the Mormon equivalent to a “Caferteria Christian.” It is someone that claims to only believe the parts of the religion that work for them. They pick what they want ‘off the menu.’ My experience is that this almost always means they are equivalent to practicing-but-not-believing. 

Anyhow, this friend told me that it would not matter to him if The Book of Mormon got proven or disproven. He suggested that if we suddenly found an authentic letter between Joseph Smith and Sydney Rigdon working out the details of The Book of Mormon together he’d just keep on believing just as he currently does. Likewise, if they suddenly unearthed a giant sign post that, when translated, said “Welcome to Zarahelma – Lamanite Parking Not Available” that it wouldn’t affect his beliefs one bit.

I agree with the first half of his assessment. I seriously doubt the second half and find it hard to believe it could be true for anyone. I suspect that this statement he made was consistent with the Menu Mormon narrative, but not consistent with reality. In fact, I doubt this friend has given any serious thought to the second possibility ever happening, so I doubt he even knows what his reaction would be nor how it would might drastically affect his life.

Frankly, I suspect finding Zarahemla would be as life shaking an experience for Menu Mormons (and Non-Mormons obviously) as finding an authentic letter exposing the Book of Mormon as a fraud would be for Believing Mormons. In short, necessary self-narratives aside, I suspect both sides are closer in this regard than they first appear. We both had ‘something to lose’ so to speak.

Thoughts?