I sympathize with you, but if they could detect the smoke that means there are carcinogens present in/on the device, and while you are free to risk your own health, it really isn't fair to subject innocent repairfolks to your carcinogens.
Apple sells expensive hardware and ---THEN---, after a year, changed the agreement to exclude smokers from Applecare repairs, and exclude smoker's machines from being repaired at all.
The real world is dusty, and sometimes smoky. Reneging on a service agreement to save money, and deflecting criticism by pointing at recent OSHA reg changes is brilliant, but a typical corporate move to enhance the bottom line. Let's not ascribe higher motive here, Apple is a business first.
Seriously, I've been servicing/building Windows clients and servers for well over a decade. The crap I've pulled out of heat sinks and fans would knock a buzzard off a gut pile. It's the job, smoking is legal, so you do it the best way you can even if you have to replace fans, etc, and then charge the customer. It's. The. Job.
I have Windows systems I built 4 (and more) years ago still operating in this company. Did I mention we're a tobacco shop? And we're smokers? I just clean 'em out, and boot them back up. Replace when necessary. Rinse, repeat.
The fact is the Imac is not robust under real life ( not apple described "normal use" ) Neither is the mini.
So my advice stands: Never buy a sealed system from Apple unless you can be sure the little darlin' will stay in a protective bubble. Or unless it doesn't breathe/circulate air, such as Iphones, or politicians.
By the by, this means ANY smoke. I'm a cigar smoker, but this means you "wake-n-bake" types better think twice. When they pull --your--system apart and see any residue in the dust, they're going to tell you "duuuuude...bummer, but..get out."