OK I am going to close this. While you certainly raise an interesting question, both in terms of sheer possibility as well as the technical aspects, I do not feel this fits our stated HR goal on Bluelight.
The fact is that each guest would have a varying desire to use each of your 3 substances as well as a varying degree of tolerance to each three. Combine this with the fact that the doses of drugs are not going to be equally divided by your patrons (the number which I dare say you cannot pinpoint to any specific number, further complicating things) because those closest to the fog machine would get a lot more than those furthest, while this might seem OK in theory when you are mixing two substances that are rather taxing on the heart (and atleast one very prone to putting one in a paranoid mindstate) with a strong psychedelic you really have a recipe for disaster.
I also question the possibility, as the only drug you listed I know to be routinely vaporised is methamphetamine, even if all 3 were vaporisable the overwhelming odds state that each 3 would vaporise at a different temperature.
Finally, even if you discounted the other issues I have already put forth, I HIGHLY doubt this has ever been done before in a documented fashion and so you could only be provided with speculation and ideas on how your goal might be achieved, this does not fit into harm reduction as often you will find a good theory has no practical application, when talking about mass administration of multiple hard drugs to a large crowd this is obviously a serious pit fall of this idea and a virtual guarantee things will go wrong.
My advice to you if you want to run your warehouse rave is to do so but let your patrons acquire whatever substances float their boat in their own time and bring it along, not only does this decrease the chances they will have a bad time but it takes away your criminal liability for the supply of illeagal drugs. I do wish your rave the best but with a join date 2 years ago it is a little disappointing you do not know better than this.