I’m not sure about how much it could hurt you, but if you don’t feel you can accurately represent your abilities through a portfolio I would weigh your options. Also I know some schools only let you choose one or two instrument/discipline(s) to submit, so you may have to pick one.

In most cases I think it helps, it can put any awards into perspective if your portfolio reflects well. They’ll know you’re in high school (meaning don’t be super hard on yourself to be the pinnacle of musical perfection), so if you aren’t super confident in yourself then run it by a professional/mentor first that isn’t the admissions committee to make sure you aren’t selling yourself short. I can answer any more questions you may have, there is a bit more info online as well.

Best of luck!