Certainly very important, but I am a little doubtful as to how well it comes across on stage; with all the dialogue and song lyrics being direct quotes there is a lot of added meaning, but at the cost of rhythm and intentionality of written or even just more edited / shaped dialogue.
I also felt that the play didn't quite land on showing the width of the act and its causes and impacts, but neither did it really allow me to connect and get to know any of the characters, who often had no real introduction, and just suddenly start speaking (often onlyin one scene and then never again).
Also this is a minor note really, but it is called After the Act (presumably because that does sound good), but only the very slim second act is after the act, the vast majority of the play charts the coming into being of the act.
But despite my critiques, I did enjoy reading it, plus I am very glad that people are talking about section 28, and I am a huge fan of using archival material, so big plus for that.