I laughed when Lin, told me years ago the story of mainland China manufacturing and quality control supervision.
Koreans are often used as supervisors and quality control inspectors. Assembly line personnel strongly dislike them because they are abrupt and strict.
But companies like Snap On, Honda, and Meanwell have Chinese factories. The same may be true for this inverter line. My Samlex 300 watt inverter absolutely has Chinese characters on it's circuit board. With supervision who cares if it's done right. The design and materials are strictly supervised.
**Snap On
Take a deep breath before you explode. Snap On products sold in the USA are 100% made in USA. Outside the USA most of the stuff is made in China or Brasil. And this ain't rumor...