If you’re looking for a mix of soil and coco, there are a few good choices of premade mixes out there. One is Mother Earth Coco Peat, and another is Roots Organics Original. They’re both soils, but have a good amount of coco in them.
My opinion is it would be better to use one of those as is rather than adding coco to Happy Frog. I’ve had great results growing autos with both of those. I’m not a fan of Fox Farm soils or nutrients
Here’s a link to my current journal. These plants are in Roots Organics Original.