Just scan the alcohol first, scan the rest next. As long as it's not the only thing you're getting, it's almost def faster. Even if it is the only thing you're getting, the time for someone to do an age check compared to standing behind 2 carts/trollies is nothing. Self check for me almost every time is way, way faster. Exception being if I have a ton of groceries (I can scan as fast as teh employees, but the self check shit has more guardrails that slow shit down) or a ton of produce (employees at a lot of stores are required to memorize the PLU, I am not.)