Beneficial fungi colonise roots and improve uptake, but only if they make direct contact, so dusting the root ball at transplant beats sprinkling powder on the surface. Synthetic feeding at high strength limits how well they establish, and the soil biology section on https://kushindicaseeds.com is honest that the benefit is modest in a short indoor run. Living soil growers see more from it than coco users. As a one off addition at planting it costs very little.