Their tuning tool gives you 90° and 88° (one side or the other).
My friend got a B-Nice at around the same time we all got our boards (she has the only Magnetraction of the group). We went into the shop the first time because we didn't know what we were doing. The shop guy detuned her board exactly the same was as our other ones, just filed a little at the tip and tail where the board curves to prevent catchiness. She's been riding it ever since with no issues (other than ones brought on by our inexperience and general beginner suckiness).
So, um... why not detune it like you would any other board and let her ride it and see what she thinks?