How is this new?
There are plenty of Chinese phones with high capacity batteries. My current Xiaomi 15t pro as a example has a 5500mah, 3.93vdc battery (that's 21.62wh).
And they just all shipping fine...
Speaking of using Chinese batteries in ROW phones: the cables are shorter on Chinese high capacity single cell batteries, so you can't exchange them in your European phone.
"tax fraud? a lot of people do it and it's just fine"