Hi Azi, welcome! I'll keep worm casting juice in mind thanks!
I've grown a godfather og last grow in a one gallon pot in LOS however I needed help and I used something called Geoflora the whole flower time. I may have used Geoflora once or twice in veg as well on that one, I forget. The Geoflora is made to feed the way LOS way so it's ok to use as far as I can tell. That experimental plant made seeds and about 3/4 of an ounce of bud that I'm super happy with. Just what I asked of it. I bet you could grow in the 1 gal pots and get an oz or two each if you topped and trained. Geoflora comes in Veg and Flower forms and can be gotten for the price of shipping for their trial 4 pound bags on their site I believe.
On a similar note, the author of the book, True Living Organics, I use feels strongly about 3 gallon self watering pots. I'm thinking you effectively can get done what he does in the 3 but with the help of Geoflora.
This is the one in the 1 gal pot. I kept her tall, you can keep them short, to be in the canopy with the rest of the grow. The purpose was to make seeds and the rest is a bonus. I pollinated one branch.
Where are you in the grow? Are you making LOS or buying?