For the William and Mary optional essay, the prompt explicitly says 500 words or less. But, the box on the common app has a word limit of 650. So, what is the actual word limit? My essay is 544 words. So, it isn’t drastically above 500. Just 44 words.
I would trim (edit) and get below 500. Generally speaking, less is better. Editing is a real skill and you’ll find you can make you essay more compelling by treating the space like expensive real estate. Don’t waste any.
Definitely cut it to 500 or less. It’s what the directions indicate, and there’s no reason to ask admissions to read more than what they’ve requested. Good luck!
My daughters was right under 600, and she was admitted ED, so I don’t think it’s a huge factor. We tried cutting stuff out, but it lost some “meat.” If you feel nervous going over the limit and can cut enough without losing content, then go for it. Otherwise, I don’t think 44 extra words is that big of a deal! Good luck!!