Very good point. The roots are mostly at the bottom and I do try to salvage as much of the coco that I can because of that. Smaller pots also mean you can fit a couple more girls in the tent!
I just started a run with my reused coco and so far so good. I flushed it until the run off ec read what the tap water ec was. Then I buffered the coco with the first feed water (made extra) a couple days before transplanting from a solo cup.
I think if I were to reuse the coco for a third time, I would do the flush to get the salt buildup out like normal, but adding some worm casings would also be beneficial. Guess I'll cross that bridge when I get there.