Why would you precommit to that? You're only supposed to do that with things where it would be good for you to do it from the point of view of now, but not from the point of view of the time you actually do it. That doesn't apply with this.

How unlikely do you think it is for you to get a feeling that the Book of Mormon is true given that it isn't? Given everything you've seen about biases, do you really think it's so unlikely as to result in the Book of Mormon being true the more likely hypothesis? If not, why bother with the test? If you know you won't believe either way, there's no point in bothering with the test.