I understand, coco is a very flexible media and doesn’t absolutely have to be flushed. One of the pros of coco is you can treat it like soil, soilless or hydro with good results.
Personally, I’ve seen about 25-30% increase in growth rate when running in a HFF/DTW system vs longer dry-backs and hand watering as you would in soil. For what little it’s worth, my first crop was in '76 and I’ve been running top feed, drain to waste coco since '95. Just means I’m old and the weed gods have mostly smiled on my efforts . . . not that I know anymore than anyone else.
I still run General Hydroponics Flora Trio + and stay away from organics in container gardening. I have no experience with Gaia Green . . . but like most nutrient lines I’m sure it works great when properly used.