I bet it is okay, but here is the flip side, if they ask for 250-300 words, than follow their direction., you are not 5, 10 or 20% over, but close to 30%.
In part this is about following orders. When we met with Notre Dame Admissions, they said the same thing as his ALO, they may read pass the 300, but at a certain point they stop...just like your WRITTEN SAT, you are expected to end where they say end.
Bullet and I have totally different writing styles, I am more "flowery" (his words) and he is straight to the point. You need to be able to get to your point in @ 300 words, not @400. By writing a 400 word essay you can be hit just as hard as someone who writes a 200 word essay...neither of you followed the directions, and the military is about following directions.
You do not know who will be reading your essay, they have 1000's of essays to read, you don't know that person, they might say I stop at 301, because they were told 300 words max and grade on that, do you want to risk it?