Ann: Oposura Mineral Resource, page-36

next best step IMO is to keep drilling and add more resources
that is, if there is any genuine exploration potential left.
more tonnage = bigger operation = better economies of scale = more cashflow = higher project value

Tangs, toll treatment is very uncommon in the industry. That's because it us practically difficult to do (processing wise) and is very expensive. Toll treatment is typically the last resort after all other options have failed, as it high grades the deposit.
Yes it might be a valid outcome in this case if there is another plant nearby, but there are a lot of steps to go through first.

Cheers
Gosouth