“First, Middlebury is not test optional.”
It is as far as the ACT/SAT is concerned, which is what this student cares about. She can submit SAT subject tests instead.
“Second, a 31 would not help at Bowdoin and similar schools given the middle 50% was 30 - 33 with an average of 32.”
I disagree. That’s the average of admitted students, not applicants. If you fall in the middle 50% of admitted students, you can be certain that you’re outperforming a lot of the kids who got denied. That is doubly true where, as here, only students who think their scores will be helpful are even submitting them to Bowdoin. Anything that puts you close to the average (or above) of admitted students will make your application stronger. You fit the profile of an admit.
Let’s say the average 40-yard dash time for an NFL player is 4.8. If you’ve got a 4.9, that’s going to help you get drafted. Being just below the average of a successful player means you’re way ahead of other hopefuls. It would be a big mistake to hide that stat, and a big mistake not to send a 31 to Bowdoin.