I know quite precisely how much alcohol is in commercial beer that I buy. I wouldn't have even a single beer immediately before an important investor meeting.
you're doing it wrong. first you drink all the booze. then you hack all the things. if your investors aren't down with that, they're in the wrong line of work. maybe they should consider haberdashery.
I can't even imagine how he thought this was a good idea. Maybe microdosing in your private office during a 3 hour block of solo time when you just want to think by yourself... but microdosing (for the first time) before a board meeting where you're expected to give a presentation?! Horrible idea.
Not defending his actions, quite the contrary actually, it's really easy to get it mixed up so I wouldn't recommend it unless you've done it a bunch of times and know yourself. Even then, that really seems like the worst time to do it.