Sub was a user of the AN nutrients, I think if you keep them at 1/2 strength they work well but dont trust them to be PH perfect because they are not. The GH mix for coco coir, Cocotek is probably the worst mix I have ever used, and Floranova is one of the best. I have good luck with Jacks 321.

Did you ever try Canna Coco? That seems like a top shelf mix for coco coir