I'm on pace for 400g in a 3'x3'
Have six autos but tightly packed.
I used roots organics soil, no nutes for first 4 weeks then smashed them with nutes. They did get nute burn but my last two plants are massive. I did add 25% perlite to the mix.
For me it's not so much how much per auto but how much in a given grow space. My space is 3'x3' I could have gone with 3 autos but I wouldn't yield 15 ounces like I'm gonna with 6. Maybe I could have done 4 and got 4 each would have been a stretch. IMO if your getting more than 4 ounces your killing it. Most ppl yielding that are using DWC, maybe some are using soil,
I'm actually changing to pro mix, I don't like not being able to add nutes in the beginning and middle of the veg cycle with autos.
Plus soil takes for ever to dry out when the plant is a seedling, I also plant the beans directly in the soil as soon as seed germs.