Remember, your experience/education CAN NOT be automatically linked to your waiver of the language exam. If you think that your ability is high enough, proof that with some concrete evidence.
We did that several years ago. We wrote a letter to show our English ability and submitted supporting evidence, such as TOEFL, GRE score and published paper. Later we were told that language test is waivered in our case. So I think it is important to demonstrate your language ability if you don't want to take the exam.