I took your original question to be directed at ReefVet, thats why I didn't respond.
Ill let you know what I've seen - it might explain why I'm using their whole system. I used to dose Vinegar, then some vodka, and even mixed up some VSV. I had good success with those carbon sources over about a year plus time period. The downside I had was that they couldn't keep the nuisance algae contained fully and the color was good but not as good as I would like. The nuisance algae was largely brownish fluffy stuff, especially on the back glass.
I went all in for the Zeovit system, including Zeolites, Start3, and their bacteria - i wanted to see if i could improve the reef. Up until that time I had a chunky, dark greenish skimmate. Within a day or two of dosing the carbon source and bacteria the skimmate completely changed to a thick, white, dense foam and within a few weeks the algae that I had struggled with was gone. Corals also responded with big polyp extension. I could never get the system dialed in to keep the nutrients low and the corals alive, looking back now I probably chased the numbers a bit too much.
I switched to NP Biopellets then their all-in-one pellets and during this time transitioned to no water changes. When I doubled the system size I made up probably 120 gallons of IO water to fill it and slowly mixed the two and the corals weathered the storm but some struggled as was to be expected.
I transitioned to Aquaforest in December and upon dosing of the Bacteria once again the skimmate changed from darker to pure white. The corals have responded more positively than I can ever remember, and the little algae I had is pretty much gone, just a bit of cyano remains. As an example of what has happened with all the corals, I had a few polyps of a small frag of flowerpot coral that has hung on, shrunk down to the rock for the better part of a year. I keep expecting it to die. Then a couple of weeks ago it started to expand. Not only is it not dead, its coming back now.
I have changed large volumes of water before, using everything from ESV, Tropic marin, IO, Neomarine etc. I used to be able to do a water change with a few buttons pushed and a few valves turned. I have never seen a huge improvement from any water change, its part of why I went away from them. The AF salt may be partly responsible for the improvement in the tank, perhaps its the combination of that with the Calcium reactor, but I think its more than that.
What all that ramble comes to is that 1) we cant be sure of any one thing, but my opinion is that the tank has undergone a big improvement since mid December. 2) Dosing bacteria like this is part of "the system" and has a positive effect on the tank in my experience. 3) This system works better than any homebrew carbon source or pellet I've used, so far. 4) I'm more skeptical than you may imagine but I don't think that you get the creme de la creme acro tank from light and water changes and fish poo only as is professed by some folks here. They may grow beautiful reefs with a simple approach but that extra little bit of color always seems to be missing, at least from what I've seen. I want the best, no compromise. Welcome to my insanity....