So if you have a 60 square hip with 150 ft of valley and 250 ft of hip you’ll have half a square of waste? And your 20 square roof doesn’t have starter and cap? Most 20 square roofs don’t have much trim scrap because they’re so simple. Who cares about 5% on 20 squares anyway, it amounts to nothing. Try doing some real roofs and then come back and tell me about your 1/2 square crap.