From another forum, someone reached out to Fishman after they had installed their pickup according to the first lot of instructions.
Here is Fishman's response
We had done some additional testing and found the neck position to have a slightly warmer tone for the mic. It will still work fine where you have it, but if you need a little more warmth from the mic, you may want to switch it to the neck position. If you need further help, let me know