"you are playing with a professionally mined out orebody."
The UG mine was halted due to low prices, not ore depletion or low grades, its likely some of this conversion risk was factored into the BFS.
Management of TRO compared to say VCN and others in a similar situation have made the right decisions until prices recover. They have kept just 102M shares, $2M cash, and at 10c, with both tailings and UG assets, which ever way you slice it TRO is cheap.
The main risk is zinc prices need to recover before the BFS will fly.
TRO Price at posting:
10.3¢ Sentiment: ST Buy Disclosure: Held