"To take one example - what assumption are you making in respect...

"To take one example - what assumption are you making in respect of the "premia"/"smelter credits"? That unknown variable alone is the difference between a profitable and an unprofitable operation."

IMO that is no longer correct, but it would be correct if nothing changed from what Q3 looked like.
In Q3 the USD price for 44% Mn was around US$5.25/dmtu. The A$5.4m of receipts for 53kt shipped at 0.74 were about US$2.52/dmtu. Approx US$2.73 went in grade discount/shipping costs which was a lot more than the market expected. This, the volume not hitting name-plate and poor communication around these issues caused the share price to collapse. At name-plate the estimated cost across years 1-5 was US$2.91/dmtu. Smelter credits would have been required to lift revenue above PFS estimated costs.

However since then

• The 44% Mn price has increased to about US$5.59 (+US$0.34/dmtu).
• Shipping costs were reduced by 45% if Top Fair sailed with its intended load (+US$0.74/dmtu or there abouts)
• The baltic dry index is at 2289 vs 3187 in the 4Nov announcement so another 28% saving should be accruing for shipping (+US$0.25/dmtu)
• Confirmation that a good day is +20% on nameplate makes averaging name-plate across the full year increasingly likely so costs divided by production should return to something close to the PFS
• Confirmation of nameplate makes expansion likely so fixed costs will spread over more production (+US$0.26/dmtu)
• Confirmation of nameplate makes expected volumes more predictable so further shipping efficiencies may be realisable
• The AUD to USD has fallen slighly and is about 0.72

These US$1.59+/dmtu of margin improvements are yet to be reflected in published results, and some won't appear until later in calendar year 2022. These gains flip the economics around and return E25 to being a profitable mining operation looking at a potentially very profitable purification project. A number of these are linked to nameplate hence why the share price is running upwards on yesterday's confirmation.

"premia"/"smelter credits" will further improve this situation but as you correctly call, by an unknown amount.