Roughly translated from Roberto Akira's page, Akira is a 65 year old Brazilian Chemist who after retiring started sharing the knowledge he accumulated in 40 years of working with chemistry.

"Cold Process Soaps are beautiful and easy to make but the process has its drawbacks. All the components added to the soap go through saponification, this strong alkaline environment spares almost nothing, it literally destroys many active ingredients of all components.
There is a mistaken belief that things added at trace will be spared since most of the lye is gone. But in reality at trace only about 10% of the lye has been consumed to form the emulsion (trace), the rest remains there and will react the same to anything that is added. The idea that superfatting at trace will protect that particular oil, usually a noble oil, doesn't quite work like that. The superfat will still be just a mix of the oils and fats in the recipe, not the one added at trace.

Therefore it does not make much sense to advertise the efficacy of CP therapeutic soaps made with medicinal oils such as Neem, Andiroba and Copaiba. The therapeutic components of these oils no longer exist after the saponification, there will be the sodium salts of the fatty acids palmitic, stearic, oleic and linoleic, that are components of Neem oil, for example, but the active ingredients that make Neem a fantastic fungicide, antibacterial, antiviral and insecticide oil, are gone.

One could argue, for example, that in the case of Neem that certain components do not react with the soda and still remain intact, but this lacks scientific evidence, more so as the unsaponifiable content of Neem is zero.

In the HP the additives, including the superfat, are added at the end of the saponification process therefore protecting the properties of that specific oil or butter."