I'd be more inclined to think you've got a tuning issue that's making your arrows nosedive rather than the arrow's FOC %. Like maybe your nock point is too high? Or maybe your bow just isn't capable of driving an arrow flat to 30 yards, with your draw length at your draw weight.

If all is as it should be... bow properly tuned and you're not dropping your bow arm when you shoot, for instance... just use your 30 pin once you get beyond 25 yards. If you're using a single pin setup, sight it in at 27 yards and that should put you close at all distances up to 30.

I certainly wouldn't advise going lighter on broadhead weight. Your arrows are awfully light already, IMO. I think hunting arrows should never be below 400 gns.