Make your roux: heat 1/3 cup bacon drippings in a large Dutch oven over medium-low heat. Sprinkle in cassava flour and whisk until a smooth paste forms. Cook this mixture, whisking almost constantly, for about 30 minutes, or until it turns a deep amber color. Don't let it burn - let this process happen slowly and gradually. This is what gives a real gumbo its rich flavor!
Meanwhile, add your celery, onion, bell pepper, and garlic to a food processor and pulse a few times until the mixture is finely chopped.
When roux is a rich amber color, stir in the celery, onion, bell pepper, and garlic mixture; add the sliced sausage. Stir well then add 1 cup water and whisk well. Bring the mixture to a simmer over medium heat and cook until the vegetables are softened a bit, about 15 minutes. Add the second cup of water, if needed, to keep the mixture from burning on the bottom of the Dutch oven.
Meanwhile, bring 4 cups beef broth to a boil in a medium saucepan. If you have not used both cups of water yet, heat the 2nd cup of water with the beef broth. Stir hot broth into the roux-vegetable mixture and whisk well. Stir in coconut aminos, salt, hot sauce, Cajun seasoning, bay leaves, dried thyme, and diced tomatoes. Simmer for 2 hours over low to medium-low heat. If you have gumbo filé, add 1 teaspoon to the soup after 1 hour.
In the meantime, heat 1 tablespoon avocado oil or more bacon grease in a skillet or the saucepan used to heat beef broth. Add the thawed okra and vinegar and cook over medium heat for 15 minutes or until sticky and softened. Stir into gumbo, along with crabmeat and shrimp. Simmer 45 minutes over low heat. If you have gumbo filé, stir in the remaining 1 teaspoon right before serving.
Serve with steamed cauliflower rice: stir in a little to your gumbo or invert a packed 1/2 cup of cauliflower rice on top of gumbo for presentation. Garnish with chopped parsley if desired.