Sorry I'm so late to this thread but I'm shocked that nobody on here mentioned
@autobeast's method of transplanting autos - I think he called these modified pots, "Transplantinator pots." I use them for autos and even for some indoor photos.. Basically, you take 2 identical pots or even solo cups. Just so that one fill fit perfectly into the other. You take one pot and, using a razor blade, you cut a big circle out of the bottom of the pot. Then, you cut out big sections of the sides; so that you're just left with thin bits of the pot left and most of it cut away. You insert this pot into another, untouched, pot and fill it with soil and plant your bean or sprout. I usually do this with 6" plastic nursery pots. When it's time to transplant a couple weeks later, you dig a hole in the new home, drop the entire unaltered container into the whole and pack dirt around it snugly. Then, you remove that container and slip it off the modified container within - you'll have roots protruding everywhere that you cut away the sides of that modified container - and you drop the whole thing, modified container and all, down into that hole you dug, and VOILA you have a transplant with ZERO shock! The plant grows it's entire life with that modified container in the soil with it. At harvest I retrieve the modified container and use it on the next round. As long as the trunk of the plant doesn't get bigger than the diameter of that modified pot, you're golden! I just wouldn't try this method on a plant going outside that'll become a tree; because the container COULD restrict the giant stem's growth.
Autobeast has the best recommendations I've found on growing auto's, in terms of training and pruning for yield! Hope this helps someone.