Why are some flavours incompatible?
Incompatibility between certain flavors usually stems from their chemical structure or the nature of their solvents. Some highly acidic concentrates, like citrus or cinnamon, can react negatively with high-VG bases or prematurely degrade certain types of plastic tanks that aren't suited for them.
It also happens that two aromatic molecules cancel each other out or create an unpleasant "off" taste, much like how mixing every paint color ends up as a questionable brown. The quality of the carrier, usually propylene glycol, plays a crucial role in the stability of the final blend to prevent phase separation. In short, following recommended dosages and synergies helps avoid bad chemical surprises. Vaping is a precision craft where every ingredient must respect its neighbor in the bottle.