companion cropping should have a purpose...
the folks that do it 'for the organic matter to break down into the soil' are doing it wrong most of the time, the scale this happens on is going to be dozen(s) of grow cycles for most soils
companion crops done right? three sisters outdoors, maximize yield of stuff you want, optimize space, and provide support for each other. cover cropping indoors is like middle of the road, kind of cool in theory but mostly a high-effort/high-energy way to solve a low-effort/low-energy problem (like soil health at the surface, or watering habits, etc.)
the real deal companion cropping indoors or out would be taking from the old ways. alfalfa companion. moringa adjacent. things that would actually boost yields from the bottom up.