Their own characteristic technology creations definitely could not be left behind. It was not that The Great Voyage Organization was stingy; it simply did not want to waste so much time. Besides, if they truly had time to produce a second set of characteristic technology creations, the other civilizations would be scrambling to get them.
Of course, characteristic technology creations with greater difficulty, such as those of the Divine Matrix Civilization, were another matter. Even if they truly built a second Neutron War Star, leaving it behind would be useless, because other civilizations simply could not enter it.
Humanity's Quantum Exile Strike could be left behind along with an instruction manual, but its production capacity was absurdly low. Even the second set, which had all been custom-made by Awakener Huan, had yet to be delivered.
The technical documentation for characteristic technology could not be left for later civilizations either, because other civilizations simply would not understand it.
After deliberating for a long time, the Four Characteristic Technology Civilizations ultimately selected only the Consciousness-Linked Warships, which had relatively high production capacity and manageable maintenance costs.
There were not many—only three thousand vessels, including both human warships and Awakener warships.
Instructions for use would be left behind as well. As for whether later civilizations would contain races with a Third-Person Dream Realm that could freely control dreams, that would depend on luck.
These three thousand warships would be hidden in the starry skies near Andromeda's central black hole. The Four Characteristic Technology Civilizations would create a concealed spatial structure there, then place the key to open it within the Andromeda Galaxy. At the same time, guidance information would be added to the Star Gate entrance passage, allowing later civilizations to use that information to find the concealed space.
Naturally, they would also