Well maybe if you team up with the Adorators of the Diggle Gods, you could befriend the Diggles. But they would just stab you as soon as you are asleep anyway.
Personally I am hoping that diggles are effectively cheap, slave labor, some kind of combination of coolies and Shoggoths.
Lower class citizens are basically slaves already. Who needs diggles when you have human capital? For the empire! For the aristocracy!
I imagine shoggoths diggles are a fair bit better at some tasks than humans are, literal walking machines. Also allowing the empire to be racist vs diggles will not run the risk of putting off real life diggles given their numbers.