It can be a little finicky, but once you get things dialed in with that mix of things you can do really well... the PK 13/14 remains one of the best additives today, just start with a light hand at like week 5, if no burn signs a bit harder week 6 on an 8-9wk strain then stop.. worm castings added during veg lightly mixed in the top soil helps a lot also..
I grew with the 5kg Coir bricks for years n years using CSN17 to feed and did very well.. then found this Roots Organic soil mix and it's just to easy and perfectly mixed and even use their foods..
But, if you find something that works for you, don't change anything if the results are awesome.. what works for others may not be your bag ya know.. best of luck bro.