How about a group of these outcasts band together and enter the employ of a rogue trader or a lord.
Find themselves assigned to a vessel that comes under attack.
Events causes them to get shipwrecked on an Alpine world orbiting a gas giant in an unknown system most of the crew is still alive.
They have no way of contacting the Imperium due to the damage sustained.
Do their best to survive on the planet with their ship acting as shelter and toolbox using everything that's onboard
Food is scarce making a large population impossible and so robots become their answer
in getting more work done without having to get more food.
The outcasts get to work in making very simple machines that aids the crew
Years later they are starting to master their immediate surrounding.
Decades later larger food supplies are found underground in cave systems but there is already creatures there competing for the fauna.
They eventually manage to start thriving instead of only surviving but the population growth is slow compared to the robotic growth.
Robots have become integral for their "new society" to function.
Centuries later the imperium (one of their allies or maybe even enemies?) finds them.
The colonists refuse to give up their robots that have been with them for so long and is a huge reason as to why they did not go under.
Administratum finds the colony interesting while AdMech says "fine but we won't help you"
Rumors spread about Korod, individuals that can be considered radicals for good and petty reasons try to reach Korod.
Their extended isolation have given them enough time to form a distinct culture, traditions and history that could be filled at a later time. (if more meat is needed)
TL:DR Tom Hanks in castaway X 5000 making robots out of the titanic on Nepal
(This will get attention)