I made a slight change to your mainscript today to involve Nividium as a "demand" resource...for a couple of reasons...
The Ashley's Fabs pack has a Terracorp Nividium mine in it these days, so there's now a factory you could attach ships to, thus (as is the case for other minerals) Nividium becomes a primary warehouse item.
Also, with the PHQ able to RE ships (including Kha'ak ships), Nividium becomes a valuable resource for import if you intend to make a lot of Kha'ak stuff. Short of buying one of Ashley's mines, you can always send out mining ships to a certain remote sector (which shall remain "nameless" here, heh) to collect bits of rock (after you blast the asteroid at least once).
Since there's no way to SPECIFY to the ships to mine ONLY Nividium, as you can with Ore and Silicon (either by factory resource demand or putting the word in the station or ship name), then I expanded some of your existing structures that check which resource to mine to now include Nividium.
I have 10 ships out there now, all collecting the valuable mineral. In this case, they have "Nividium" in the ship name, so it's the only thing they look for.
The really funny part, though (and a tad ironic, too), is I have two former Kha'ak scouts out there on rock-breaking duty.
Anyway, I might suggest making this a part of the official version since mining Nividium can be a worthwhile endeavor now.
If you'd like to take a look at the changes I made, let me know.