“My father even found a Rishon (I do not remember who) who said that in his time it was the custom of the young people to “taste liquor” before Musaf. So the custom goes way back and if done in a respectful manner, it is not the end of the world.”
One crucial question, did the rishon say he agreed with those “young people” or not? People doing things wrong years back does not an acceptable custom make.