I took the CFA at NASS this past summer, and honestly the way they did it, the odds of you getting your best score there are fairly high (the huge numbers at once led to slightly longer waits between events). I don't think I maxed anything (maybe sit-ups, I can't recall), but when I went I talk to my BGO in September, he said what I had done was fine.
Part of what you want to look at is when you will be in the best shape. I had just finished my spring sport season and was two weeks into summer swim, when I took it at NASS. If I had done it later in the summer, my scores would have been hurt by the couple weeks I was in situations where I had no workout opportunity.
With regards to taking it multiple times, my impression was that Navy allowed as many re-takes as you want, but at least one of the other SAs did have a limit. And yeah, no super scoring.