There has never been a definitive consensus in the industry regarding the use of camera angles during kissing scenes.
Back in school, teachers would touch upon the subject, but they never actually taught it. There was no distinction between academic and unconventional methods; it was all up to the actors themselves. Some directors demanded real kisses, and if the actresses had no objections, everyone complied. Other directors held less sway, so if the actress wasn't willing, they would use camera tricks. Even camera tricks varied: some were just kisses to the corner of the mouth, some were lip-to-lip contact without using tongues, and others avoided contact entirely, using the actor’s head to block the camera's view.
Chen Ming’s method was different.
Chapter 58