Now really seeing and looking over the videos of YSF it's obvious that Max Adler is the one that's really been trained to my on stage. He was always the first to immediately respond to certain things (ex. standing up and posing as a "One Direction member" for a poster, pretending to be a "fan of One Direction" by flailing and screaming, or willing to be naturally "cozy" with Dottie as a couple).
I know he done some singing back in the day, but I never heard of him really being in an acting class, or anything, but with how he responded it seemed obvious he's done a lot of improv games and what not. Either that, or he has a natural talent for improv. Which I wouldn't doubt since I've always thought he was an amazing actor, but it's interesting to see something more comedic and he's a natural at it.