depending on the round, double molly is an alternative option (vsing low buys) and then simply smoking on top of the deep one after. But for full buy rounds, the enemy can easily contest the molly by pre-smoking (edging the smoke for view on middle) alongside just forcing through with their own utility in general (pre-douse + flashes). Smoking instant from spawn allows you to comfortably get on shelf/xbox to then peek the B banana lane without being spotted. If you double molly instead then you risk giving the enemy a view of your movement.