When the crisis arrived, it was already normal for civilizations to open their borders to each other.
When the Galaxy Focus: Enemy was proposed by the Pyro Alliance, open borders for member civilizations were one of the additional requirements of the proposal.
After this proposal was passed, all civilizations could communicate with each other. At the very least, the inspection procedures for spaceships crossing the border would not be as strict.
One of the most important uses was to increase the efficiency of the stargate. When the Milky Way civilizations were conducting long-distance intergalactic voyages, they usually used the pseudo-megastructure of the stargate.
It did not require high technology and resources to build. Even civilizations like the Star Alliance could build stargates as soon as they flew into the sky. Many researchers did not consider stargates as megastructures.
