The investigation into #19857 has led to the need to warn developers to not make hasty assumptions about android default font fallback. Devices (notably Samsung devices) may choose to use varying fonts as default fonts, and thus cause Flutter applications built with the expectation that fonts remain consistent will experience unexpected behavior.

Specifically, Samsung uses a font collection called SECCJK-Regular.ttc alongside default NotoSansCJK-Regular.ttc which causes CJK text line spacing to be smaller than other devices'.

Documentation should be added addressing this to prevent confusion.