I am not following Lynas Corp anymore so the future may be brilliant. But if you take Lynas as an example for NioCorp , then please look at the long term chart and try to understand the agony longtermshareholders went through since 2010. I exitted Lynas long time ago with a nice profit before the Chinese destroyed the rare earth market and I remember the issues Lynas had in Malaysia.
So it depends on your timing whether you are a happy shareholder in Lynas; ( as for most investments timing is important).
I think timing now is still favourable for NioCorp though.