I've been using BrewTan B (off and on, mostly on) for about 2 years now in both the mash and the boil. I think, if there is a difference, it is something you will see down the road after packaging. I do notice a difference in clarity initially so I have chosen to continue to use it. I would recommend dissolving it first before the mash as well as the boil because it gets very clumpy (unless, in the experiment, you were dissolving it in the strike water.)
It is very expensive so I'd love not to use it but I do believe it may help with shelf life. But OTOH it is very hard to judge that on the capacity that I brew on.
The only question I have about the experiments is - why on the Earth would any one ever brew a CDA?