Artisanal output from eastern Democratic Republic of Congo, north-western Tanzania and western Kenya has long moved toward Kampala's buying and refining capacity. The differential is not geological but institutional: Uganda offered a faster, cheaper route to a buyer.
That institutional pull has been remarkably durable across changes in Ugandan policy and regional political conditions, which is itself informative. It suggests the incentive gap between Uganda's buying infrastructure and that of its neighbours has been large and persistent enough that incremental regulatory tightening on the Ugandan side alone is unlikely to redirect the flow quickly, absent equivalent improvements upstream.