When a calendar says, "Heavy feeding"

Does that mean "Miracle Gro" or "Fish emulsion" or "Doesn't matter?" :huh:

I would say the amount of fertilizer depends on stage of development and your goal with the tree. What product you use is less important.

Normal maintenance. All are established growing trees.

So just fertilize according to manufacturer recomendation at first and adjust as you get more experience and understand better the development phases and the goals with your trees.