Spot on Shimmer,LYC Mt Weld is also carbonatite but its...

Spot on Shimmer,

LYC Mt Weld is also carbonatite but its mineralogy is primarily phosphate based.
ARU Nolans Bore is also phosphate based as you mentioned.

Ngualla is fluorocarbonate (bastnaesite and synchesite).
ARU/LYC may not be good comparisons for any OPEX/CAPEX or processes flows.
IMHO based on what we have already seen on the metallurgy and that word "carbonate" PEKs initial process flow might be cheaper, more efficient, and have a much lower CAPEX.
Although who knows what happens once you get to the solvent extraction phases.