It was already the most capital intensive project (from memory)....

It was already the most capital intensive project (from memory). A blow out would be a concern for the whole sector unless it is shown that it is a cost very specific to KLL.
The SO4 Lake Wells scoping study compared to the Lake Way DFS was a massive blowout. All these projects are much more expensive than anyone originally thought.
Back in the RWD glory days, a Shaw Stockbroking research note estimated the LD capital cost to be $150M.

But KLL look to have been very methodical, it would be very surprising to see a major cost blowout.