The end of creativity, here comes reason
If you are a fashion guru who can't do without having to edit every bit of his life, leave out at least the holder, in your own interest. Although the heating stick may be a little boring, rather have a free engraving at the IQOS Store if you have to do something with it, but do not stick anything on it.
Do not experiment if it can cause harm to your health. Non-original accessories are not tested and may damage you or the IQOS.
Every day we are wondering if Philip Morris adds some dangerous stuff into HEETS, yet we somehow suddenly stop thinking about our health when it comes to putting stickers on it ourselves. All stickers contain chemical substances and adhesives, which can release several times more pollutants than HEETS. Some might be ok, some might be the opposite. Do you want to risk it?
How about caps from China?
While writing the article, I realized that not only stickers are not tested for warming, but can see all sorts of unofficial accessories at each corner, as well as holder caps that come in many different colors. You can recognize them as they do not have the IQOS sign, which the manufacturer uses as a trademark. Do you know what these caps are made of? I don't, but I don't want to find out at the cost of my own health.