Roots in Coco

Microbes could help off set some bad microbes if they get into the mix. but primarily they are to help breakdown stuff and make it plant available. Like Numbers said the feed is already available so it won't be adding much of anything in that sense for nutrient avilablity.

Coco is inert, so you are providing 100% of nutrition. Most likely this is a 'hydro' type of nutrient system that is 100% plant available and 100% soluble. So, no, the bacteria won't help much becuase their primary benefit is not needed with such fertilizer. also, if you want healthy roots, use 67% coco/ 33% perlite (or similar) in future. The 70/30 prepackaged options are good enough, too. a top-down watering is going to be helpful if you are normally bottom-feeding. This bottom feeding takes one the primary advantages of soilless growing and throws it in the dumpster. It's not a good idea for soilless growing. 10% runoff is essential to maintaining an equilibrium concentration of nutrients in the substrate. bottom-irrigation will potentially cause a buildup of nutes and require a top-down irrigation occasionally to avoid it. Any time you have to give water-only to dilute the substrate it slows you down.. it's less than idea even if it can work okay.

All salt build up is in the top of the pot . Running anything threw it has risk of nute burn. Unbalance of everything ph etc... Barking up the wrong tree with recharge and 100%coco.. sounds like you want to go living soil. Coco is inert.

You're going to need to amend to some extent if you're trying to keep a living soil, which is a hard sell with 100% coco. What is the goal? This may be my organic chemistry showing so keep me honest but I would never use any microbes, living soil amendments, or natural sugars when using chelated nutrients. Isn't your primary line chelated??