This may be pretty old, but I didn’t find any posts so I decided to post the tooltip discrepancy here. This bug only affects Engineers.
There are three skills associated with the Elixir Gun Kit which are categorized as “Elixir” skills (as can be seen in the tooltip) which are unaffected by any traits that are supposed to have an effect on elixirs (e.g. HGH, Cleaning Formula 409). The three skills are “Acid Bomb” (default Kit 3), “Super Elixir” (Kit 4), and “Healing Mist” (the associated toolbelt skill). I tested all skills and trait combinations in and out of combat. None of them seem to actually be behaving as Elixirs.
Comment: As usual, I don’t really care how this is resolved, I would like to see the game behave in a manner that is consistent with the tooltips. Obviously, these skills and elixir focused traits would become quite a bit more powerful if they behaved as the game suggests they should (the cooldowns on these skills are quite low). On the other hand, you could keep the current functionality and just bring the Tooltips in-line with the game behavior.