Containing gardening has been quite challenging for me if I choose to avoid the soilless system of peat and soluble plant food. A cubic ft of mineral soil is not the same in a container as in the ground. It has more air to it, heats up and dries out easily, organic matter breaks down faster. The initial fertile soil with good texture quickly turns into a lifeless brick. Usually I need to amend native soil with lighter materials to reduce bulk density and add water retention. If you are in a dryer climate, drip irrigation with just the right amount of water would save a lot of work and reduce nutrient leaching.
I have no experience with cover crops in container. When I set up the pot (mineral soil + biochar + compost), it is ready for planting. The fertility hardly lasts for more than 2 months due to hot and humid weather. I would regularly add healthy plant materials as mulch or weed tea to get the plants fed. So far, my container yuzu tree and tropical flowers are doing fine without frequent repotting.