Hi, author here. I believe I did discuss this, and in fact, I list the same a) and b) conditions you mention using slightly different words. Quoting the articl

Hi, author here. I believe I did discuss this, and in fact, I list the same a) and b) conditions you mention using slightly different words. Quoting the article: "To benefit from the async style, an application needs to have tasks that are often blocked by I/O and don't have too much CPU work." So I think we agree.