The complete mystery re: which elements of an application and interview are must-have or must-ace and which are ignored entirely, downplayed, or even taken as "red flags" ("what might that be?" wearing a suit to an interview, or just dressing above business-casual—required some places, practically a guaranteed "no" others) is one of the most frustrating things about interviews. Which is saying something, really, because most things about interviews are pretty frustrating.
I'd recommend presenting yourself and dressing as you'd like. You'll attract companies that are a better fit than one where you're fumbling for the "right" way of doing things.
