My guess is that you've got a fundamental problem with the plastic used in the airflow section, and that if you were to give it to just about any random person to try, they wouldn't have a clue what you're talking about. It happens - some people are just really sensitive to things that wouldn't even register with other people, and fractional parts per billion is enough to trigger the "overpowering" bad taste. (I have my own problems with several things.) It may just be a matter of time, or it may be something that never goes away from your perspective. AFAIK, there's no way to take off the AFC ring that won't involve destroying the tank, and if the plastic's the problem, it wouldn't help anyway. (The plastic is there so you can get an actual MTL on this version, which the OG Ares didn't offer - it was about a 1.6mm draw fully closed off.)