No, I am not an expert of 4-manifold theory and would not really understand most of the chapters. If this book fixes some of the literature issues in that field that is amazing! Does it finally resolve the issue of nobody understanding the construction of topological Casson handles?

Edit: I see from the MO comments "The fully topological version of the disc embedding theorem is beyond the scope of this book, since we will not discuss Quinn's proof of transversality."