If you feed your plants, it doesn't matter what dirt you use.
We don't feed, we use living soil. All amendments up front and nothing but water afterwards.
We've yet to have any issues or deficiencies since switching from the FFOF. Before we had all kinds of problems.
Welcome to the Farm, I use Pro-Mix and ro water or rain-water, never tried FFOF. These guys here are top notch growers who have helped me a lot. Keep it civil & they will help.