> I don't know engineering wise why China model phones can't ship with both dual physical slots and support any combo of two physical/eSIM. There doesn't appear to be any obvious technical limitation.

As far as I know Chinese carriers don't support eSIMs for smartphones yet. I'm not sure if Apple would have been able to legally ship eSIM support in China, but even if they would be able to do that it would be an additional cost for a feature that nearly none of their customers there would use.