If He Bingjiao has played as many tournaments as her peer Akane Yamaguchi, she would have gained the much-needed exposure and enough experience to be considerably less nervous as she claimed she was whether on semifinals or finals days; after all, the NZ GPG is not a major team championship where she has to carry the nation's hopes.
She might be overconfident in the 1st set but would most certainly be worried and played with more sense of urgency at the start of the second. Personally,I feel her fitness is really suspect, a serious drawback esp when facing a strong, tenacious retriever as evident when at one point after a not particularly long but punishing rally, she was holding her stomach in discomfort visibly and bent double while panting heavily.
Not only HBJ herself but her coach too, I believe they would draw the right lessons from this defeat as well as the earlier one at the CHN IC where she was summarily beaten by Nozomi Okuhara, another very capable retriever and skillful player. As long as she is willing to work hard and learn and has the right attitude she will go far with her talents.
For a dynamic attacking player like her, fitness becomes even more important, vital. IMHO, without sufficient fitness, it's useless to talk about tactics. If possible, she could train with Wang Shixian,a superb retriever, to help her build up endurance and the ability to keep attacking and pile on the pressure until breaking point without sacrificing too much accuracy and becoming erratic or turn wobbly easily.
At her present age of 18,still quite young and in the formative stage of her career, I cannot expect her to be steady and composed, a trait which I can only hope she develops or acquires as she matures and accumulates experience. To do this, there is no other way than to compete actively and regularly in as many tournaments as possible even if it means suffering a couple of hard knocks which can only strengthen her if she is meant for great things.