They are psionic, not magic, I assure you of that.

How about, if they get DNA, or good enough scans, then a generation would be made of them.

So:

Supreme Draconians, Urgarians, Hyllians, and Ylfrish. Those are known to them.

And no, they just explore universes, they have not the time or the strength to mine them. They just mine what they need when they need it, from the closest richest source.