Only thing i've seen on his site are threads discussing or trying experiments as such with no actual evidence proven in the end result, just more questions raised. What i'm going to go off of is my 20 years as a fish hobbyist, breeder, and the experience's and discussions with the hobbyists, and shop owners i've networked with over that period of time. One thing i have learned through my trials, and tribulations is no one is a senior of anything, anyone can be wrong no matter how long they've been doing something, and anything is possible, and with how many times people have told me i was wrong, but i ended up being right eventually or partially it's worth being skeptical about everything.
Another concern is it's ever growing strength evidence activated carbon dust might be a cause for HITH, so for me that alone is something i would avoid the possibility of all together by just not using it.
Now as a example what would your thoughts be based on this article on my main forum, as i'm open for discussion as i can be wrong myself, that i can admit. So these talks are always healthy to have :-)