The main form of propulsion used by the Tratias Ru, Mass Dilation Drives reverse time dilation using exotic matter of negative mass to make trips around the cosmos thousands of times faster than Alcubierre drives and thousands of times easier than wormhole drives.
A Tratias Ru spacecraft with an MDD can do around 1000ly/s, going between the Via Sagittaria Galaxy and the Aylothn Galaxy in about 5 and a half hours, much better than the 2,000 years that Human Alcubierre drives would have to endure.
Why no-one uses them
These properties make them an ideal drive for expanding species such as the Humans to use. However, because the Tratias Ru don't want to expand but rather upload every Tratias Ru to a simulation, and because the Tratias Ru are especially hesitant to let anyone else know about MDDs, no-one has been able to use an MDD for themselves.Using MDDs in everyday travel has become a pipe dream to many advanced species within the Ambrosia Galaxy.
Recreating the Drive
Humans have recreated MDDs before, however they have not been able to make them anywhere as fast as an Alcubierre drive, let alone as fast as the ones used by the Tratias Ru.
The Zythyn recreated the drive after the Humans' attempt, being able to push about 1105ly/s, however their testing craft were prone to being torn apart by uncontained negative gravitational forces.