Okay, i am tinkering a bit with basic elixirs and, for now, only herbal grind, to get a grasp on how the system really works.
Up now i found that mixing two ingredients with the same wound type DO NOT give an elixir wich heals the mentioned wound (example: fluorspar and yellowfeet), but the common parts still are present in the final product. Instead, the two "wounds" elements paired will often leads to an healing result, but with a different kind of wound healed, not sure if there's a relation between them up now.
Herbal grind looks like to maintain the doubled elements in the two ingredients, but re-randomize the other ones, and up now they lead near always to a four elements ingredient. I was able up now to determine very few of the herbal grinds elements, but i do often get more than two skills/stats from them, wich looks nice.