vaporizing mxe, not smoking it... works fine. anything that is normally smoked for its effect can be vaporized. however it would be smart to use a high-end vape pen that allows you to change the temperature, since these chemicals all burn at different temperatures. i have only done this with heroin, but i think i can give you some advice on doing it with other chems. first off, obviously look up the vaporization temperature of your chemical of choice. if it is higher than the temperature recommended to effectively vaporize your nicotine juice, you should use less nicotine juice relative to the chemical. you want enough juice to dissolve the chemical (which in heroin's case is quite a lot), but too much juice and you'll be burning up that juice to the point where you hurt your throat and lungs too much to inhale enough chemical. and if the temperature is lower than that required to vaporize your juice, use a generous amount of juice relative to the chemical. the thing you have to consider is that if you put a dose of the chemical in there, you're going to have to inhale the entire cartridge to get the full dose. this is why i used to put 10 times the dose i was trying to get. there's not much danger for overdose because the chemical will absorb immediately when you smoke it. you'll know when you're starting to feel it, and you'll definitely know when you're on the level at risk for overdose. i've never heard of overdoses on 7-ho-mitra but im sure its possible, but probably very difficult to do with this route. of course you need to find out the solubility of your chemical of choice in your nicotine juice's solvent. to my knowledge all nicotine juice is oil, so if you can't find the specific solubility, just use your logic. if you can get high off the chemical by gumming it or putting it under your tongue, then it obviously permeates mucous membranes (made out of lipids), so it will definitely be soluble in most oils. some chemicals that have very low sublingual bioavailability will still be soluble enough to get high this way if you use enough chemical relative to juice.
in summary, it should be fairly easy for you to find the temperatures necessary to vaporize most chemicals youre trying to do, as well as their relative solubilities. if that fails, use common sense and experimentation. of course, you shouldn't play guinea pig if you're about to do a dangerous chemical. benzodiazepines are variable in their lipid soluble, but i know midazolam is extremely lipid soluble. it would not be dangerous to do a shit ton of midazolam this way. you would have to inhale hundreds, if not thousands of cartridges to actually die, though you may pass out haha. i really have no idea. with regards to opiates, most of the familiar phenanthrenes have poor solubility, even heroin and hydromorphone. fentanyl (and related chems) and etorphine-based phenanthrenes generally have much better solubility. fentanyl shouldn't be too much of a challenge (even with the current matrix patches, you can extract it nearly pure with IPA) but good luck getting pure etorphine or buprenorphine lol. then with regards to MAOIs, i don't know their lipid solubility. just look it up, i'm sure it's out there.