You might get better answers but probably not optimal ones? I imagine the avoidance of technology leads to inefficiencies that most people would want to avoid.

Maybe the permaculture people, or intentional communities that seek to be self-sufficient (as a community); perhaps kibbutzim hold useful knowledge here?

Amish do not avoid tech, they test it and see pro/cons and then they take a decision if it will get adopted or not. They have a lot of tech enthusiast that will try new tech and then the elders will decide to keep it or not. And they strive for self-sufficiency 100%.

Depends on which inefficiency you want to avoid. Do you want to not use modern machinery, or do you want to pay for modern machinery? Each approach has a cost, in different ways.