Based on my background in HR, I will say that your cover letter is key. If it doesn't come off as genuine and well written, you're doomed. If it doesn't tell me what I'm looking for, you're also doomed. The latter is subjective, the former is more objective. I would highly recommend getting people to read your cover letter who will be honest with you. The CDO will do that for you and at least give you their opinion. Colleagues may also do it for you, although their expertise will differ. But try to access as many people as possible. I have seen some horrific cover letters in my day, and the writer, once asked, had no idea.