Interesting feat indeed. 18 Bil in my vanilla X3R game does have Trading Station, Pirate Base, and 7 Factories. Pirates are random, so do not count those. Trading Station is quite near the spot where the Xenon spawn, but there are Asteroids to confuse the Xenonic gerbils. And the Factories are all westward from the TD. So getting the Xenon K see and catch all of them ... after all the K has only Triplex Scanner, so it cannot possibly see all the stations when it jumps in.
But X3R has GoD. GoD may have removed Factories, so perhaps there were not so many stations to start with. And I have a faint recollection of a Factory due SE from the TD. That would explain part of it; there were only couple stations, and in "favorable" positions.
And GoD is the one making Factory judgement. It can build Factories and remove Factories. Positive and negative economic events. It remains a mystery, how often does the GoD act, and what conditions do decide the nature of the event. Pray the Almighty Random Number Generator, and you might see Factories there again. Or trade in "right way". (Yaki demolished Power Circle in my game, and it has remained so for quite long now.)
Trading Station (TD) is a "governmental" installation. Those do respawn after a while. Always. Perhaps 12 ingame hours or so.
But as said, XI should be advertized on all sectors of the target sector race within 3 jumps or so (actually within 3 galaxy map sector indices). So no apparent need to worry.
