[NEEDS VERIFICATION PASS: this node's claims about specific clan names (He and Liang of Panyu's Jiaotang Division), the precise red-flag inscription, and the characterization of smoke-den demographics in Guangzhou's Xiguan district require independent sourcing before publication — see verification note on n03.]
What is independently well-documented: domestic poppy cultivation did spread inland over the 1820s and 1830s, particularly into Yunnan and Sichuan, as the habit became profitable enough that growing food crops lost out to growing poppy in some districts. Lin Zexu's 1839 crackdown, including the destruction of opium stocks at Humen, is extensively documented and targeted both the foreign supply chain and domestic trafficking and consumption alike.
The pattern repeats from the coast inland: a habit that started as an import becomes, within a generation, something grown, processed, and consumed entirely on Chinese soil, by Chinese hands — while the capital that had originally primed the market, and the silver it had already extracted on the way in, never had to be local at all.