Pilot plants are built and operated to gain knowledge and prove...

Pilot plants are built and operated to gain knowledge and prove the process, not to make money. They don't have economies of scale and require more skilled research staff. Once you have operated the pilot plant and gained the knowledge you were looking for it makes sense to shut it down and save money.

The NTU resource is relatively low grade (as are most) at ~0.9% (from memory) with half being the cheaper Y and the rest high value Dy and Tb.
The game changer for me and the reason I have progressively bought in is the success they have reported with the mechanical ore sorter. With a relatively simple processing step they can raise the grade from 0.9% to ~25 to 30 % (again from an unreliable memory). This is a huge benefit for the process economics. Building a full scale plant near the mine where summer rains will require an annual shutdown and skilled workers are scarce would be a big drag on economics, therefore rather concentrate it up and transport it closer to civilisation. Unfortunately the distances are large.

The government is funding Iluka ~$1 billion for building a rare earths processing plant and in all their presentaions they mention the plant is encouraging "third party supply of feedstock", so surely it makes more sense to NTU to produce a concentrate for sale to ILU's plant, than try go it alone (without government funding). ILU and NTU ores are both xenotime (rare earth phosphates) so should be able to use the same process plant.

Another catalyst that looks interesting was when Curtis was hired and then signed an option contract with some existing shareholders, again from memory, to buy ~$20million NTU at ~11c within 2 or 3 years.
His recent role change, (with, I agree, a ridiculously high salary for a non-operating company) suggests something promising is on the horizon, because they will need a capital raising just to pay that salary and no one is going to cough up unless there is concrete progress.

Another thing to be aware of before making a decision on NTU is that there are a number of NTU hating trolls, probably disgruntled ex-employees/shareholders or competitors (e.g. Lynas, Hastings, ASM or China) that are always ready to come out of the woodwork to bad mouth NTU and Curtis.
AIMHO