Arrow length is just one of the "tools" - along with draw weight and tip weight - to fine tune the arrow spine to your bow. I use the charts to get in the ball park, and then start with full length shafts - comparing fletched shafts to bare shafts at 20 yards, cutting an inch at a time off of each -until the bare shafts are hitting the target straight and at the same spot as the fletched ones. Too long/soft of a shaft is going to print the bare shaft angling to the right of a fletched shaft. Once I get the two shafts hitting the target straight and at the same place, it doesn't really matter to me if the broadheads, at full draw, are 1/2" ahead of the arrow rest or 2 1/2" forward.

Having already done some bare shaft tuning with a Fred Bear Instinct, I would suspect a 400 series Easton arrow at about 30" with a 100 grain head would be very close - assuming the 58 lb draw was accurate. I don't think you could get the 500 series shafts short enough to spine out, without reducing point weight and/or decreasing the draw weight, at your draw length.