@gosouth observes (correctly) that strip-ratios are likely to be higher and mineralisation not as shallow as expected.
@dolcevita says in response, "well that's a rare admission. Something positive" (and receives two thumbs!)
Pro-tip Dolce: High stripping ratios are not a positive thing. Generally, higher strip-ratios mean greater costs (because unwanted ore must be extracted to reach the mineralisation which adds cost & complexity to operations).
High-grades may support a high strip-ratio but as @gosouth, @salpetie and others have already noted, the grades we're seeing at Oposura are underwhelming and landing at the low end of expectations.