Three of my friends independently had a "drink and blow" party. All of them reported that the "insipid 0.8 B.A.C." was the drunkest they had ever been since back in the days in college. In fact (warranted or not) one of their take home conclusions "if you feel fine, don't worry at all about blowing past
So you're lightweight friends can't handle their booze, how or why should that impact how the rest of the real world works? Being responsible is something you have to plan for and if you can't then don't go out or don't drink. Aside from that and that breathalyzers are notoriously flaky, especially the ones regular losers can get their hands on, and can be challenged in court pretty easily.