They have done the process engineering (FEED) for a plant that...

They have done the process engineering (FEED) for a plant that sits adjacent to railway lines, a gas line, road & power station with a skilled workforce nearby. There would be significant costs associated with choosing an alternate location which if anything, is a ridiculous situation for TNG to find themselves in at this stage of the project development cycle. Someone is responsible for that ridiculousness. And at the moment we really don't know who.
That said, because the process engineering has been done, provided the above are available, the plant could be relocated. Port Augusta, anywhere along the Darwin/Adelaide railway line where that criteria intersect, overseas which would be the worst possible outcome for value adding to our raw materials so Australia benefits the most.

As part of the SMS engineering they would know what is required from a replication point of view - IOW to build the TIVAN process elsewhere. This would likely include adaptation of the TIVAN process to mineral sands feedstock - IOW enhanced processing capability from existing players - Tronox, Iluka etc.

Development/proving of the process is where the hard work is done.
You could copy all the same equipment, arrange it in the same order, but if you don't know how it all works together, dosing rates, flows, pressures, temperature, dwell time etc you really don't have much of a chance of it working.
And production guarantees will only come with SMS having that knowledge which no-one else would (IMO).
So a patent is only part of the protection.