After some research, it appears your right, there are a few .380 single stacks at under 16 oz. ( some at 14-12oz)S&W M&P Bodyguard380 no laser
most 9mm's are above 16 oz ( 20-24 for some) but you get alot more fire power.
so if smallest and lightest is the goal, .380 still wins over 9mm.
it'd be neat to see a single stack .30 sc, that could be pretty light and thin.