Experts neeeded

They need big containers and living soils (worms, mites and everything) in order to make any sense. Nitrogen fixation is very very slow, don't think it would help much. Only useful for protecting soil from lights. If you don't grow no till big containers it's better to just cover pots with a mulch layer and forget about cover crops. Even then is preferable to grow cover crop in between cycles, cut it and leave it to decompose for some time in the container before planting weed again in it. Even if a remote possibility, weed can get stunted from growing with companion crops.... as someone said: "you don't want your cannabis plant outcompeted by some clover" Regular straw mulch or something inorganic like expanded clay, sand or lava rocks on top of soil will slow down evaporation and keep more consistent humidity from the top to the bottom of the cointainer. This will result in a stronger root system with well developed feeder roots in the top portion of your containers. Just my opinion on this matter.

growdiaries.com/diaries/122902-grow-journal-by-stinkyfingerz I’m having great success in a 20 gallon. To many advantages.

I personally have done clover in vegging for the extra nitrogen it pulls from air. Plus it gets shaded out and pulled in flowering. Don't want the nitrogen then anyway. It worked well. It was pre diary days. Think I got a video on my YouTube channel from new years last year where I have it documented.

Growing companian plants works for several reason. It depends on what you want. It also depends on how and where you grow. I grow out door and my vegging can goes on for a few months. I grow pig weed or floweirng porculata with my cannabis. Pig weed root produces root stimulant and feed beneficial soil microbes. Works really well. But cannabis grows much faster than pig weed and I need to prepare mature batch before planting cannabis. The benefits outweight the cost of extra fertilizer. Also for out door, there are insect repellent plants, nitrogen fixing plants, etc., take your pick. And there are plants to avoid, for example anti-beterial plants that harbors mold. For auto, commanian plants may not have time and space to work as well as out door grow.

Servus Mate, you mean companion plants? Absolute no fake, works very well. Have a look at Royal Queen Seeds or Zamnesia. They sell companion packs with all different little helpers.. Clover, Dill weed, borage and and and.. One big disadvantage in my opinion, the more companions you have around your Senorita the more hide outs for bugs.. 🤔 Hope this helps a bit. Good luck, Servus ✌️