Ooooh popcorn thread!
Can it be done? Maybe, I believe
@Florida Bullfrog is doing a similar thing his youtube videos are quite informative and entertaining. He has got his hands on some actual feral chicken stock though I believe (I could be mistaken on this point). Is it possible for most people in most places? Probably not. I'm not sure if breeding in modern dual purpose lines would help, they all are giant piggies. My flock are great at free ranging for their food (grass, weeds, bugs, seeds, mice) but they still pig their way through what I feed them and still lay like they just don't care they're supposed to lay eggs. Ok I'm being a little unfair they've just finished their moults and they're not production layers.
If I had 10+ acres of prime forage land managed as an ecosytem and multiple fruit and nut trees maybe they would manage. There are certainly feral populations here (but only from dual purpose stock that's been dumped not actually feral chickens in the true sense). But I doubt they are productive in any way. If you want to shoot chickens for meat as needed then I can see it working. If you want eggs etc in any predictable way then probably not.