Hey there. We are in west Florida, and our family has been gardening and growing food here for over 40 years. In a nutshell, I have learned that keeping the soil cool, which in turns keeps the roots cool, is the most important thing when trying to get your veggies to thrive long enough in the high temperatures. This is why many southern gardeners use the hot part of summer (now through beginning of August) to solarize and rest the gardening areas, ie mulch fertilize and wait. Then in late August and early September plant the fall plants including another round of tomatoes, cabbage, etc. Lettuces all winter. Potatoes anytime that’s not summer. Garlic and onions anytime that not summer.
You say you are using containers, are these wicking bed containers? If not I would highly recommend wicking beds. Otherwise you gonna be watering every day like my dad does when the hot breezes come through and dehydrate all the plants.
I grow very little in containers, but what I do have is grown fully in rabbit manure and still has to be watered every 2 or 3 days unless it rains. Peppers, basil.
I grow a ton of stuff in wicking beds, but realize that the things I am growing are not conventional vegetables and they can handle the heat, ie water spinach, water hyacinth, canna, taro.