One might find it odd, given the yinrih's longer lifespan, that they were able to achieve spaceflight a mere five thousand Earth years after achieving sapience. This would be like paleolithic humans going from hunting and gathering with sharpened sticks and hand axes to manned orbital flight in a mere five hundred years.

One obvious contributor is that the yinrih had been able to write from the word go. Being able to preserve thoughts over time and space, allowing their collective body of knowledge to start building up over generations. The second reason they progressed up the tech tree so fast is that most scientific progress was done under the auspices of the Bright Way, which had (and to an extent still has) a strong martyrdom culture. Giving one's life while furthering the goal of finding other sophonts among the stars is the highest honor a Wayfarer can hope to achieve.

Combining religious zeal and scientific curiosity makes for a rather high casualty rate among yinrih scientists, engineers, and explorers, willing as they were to take greater risks in the name of fulfilling the Great Commandment. In particular, the yinrih didn't so much dip their paws into the starry firmament as hurl themselves headlong into it. It was less NASA and more Kerbal Space Program. Less than a score of humans have died while attempting spaceflight, but the yinrih have a litany of canonized martyrs (and cannonized martyrs, given their earliest attempts may or may not have involved shooting people out of a cannon in a vaguely upward direction), all of whom made the ultimate sacrifice while pursuing greater knowledge.