All your points begs the question: How many units per month could Yihao's 200,000 facility pump out with approx 50 machines? My guess nowhere near enough for Apple, possibly enough for the P30 if they started production stockpiling months in advance, and definitely ENOUGH for the ASUS Zenfone 6 camera housing.
Unless of course, Yihao had OUTSOURCED much of the production to "other CM partners" in Lugees MAZE, then mass production is here....