I was more thinking if there could be shared infrastructure of a...

I was more thinking if there could be shared infrastructure of a crusher, or sorters. Flotation as far as I'm aware will be different, as gold is leeched usually with cyanide and lithium with hydrochloric or sulphuric. Lake Johnston plant is interesting for the lithium, that will help with cost.
Toll treatment depends on the minerology of the gold I suppose, if it's complex, no one will take it. Even an optimal ore body could be treated poorly due to not being set up and adjusted for that ore perfectly. So many moving parts, and questions. If I was in Australia I'd be ringing up and asking.