Re: upsetting a lot of the other jurors.
IANAL, but IIRC, a juror is prohibited from using their own knowledge in deliberation. At least in California, probably much more widely. So, for example, if a Nobel-prizewinning Genetics/DNA analysis researcher were to be impaneled, they must _NOT_ make any comments in deliberation that relate to their own knowledge.
IANAL either, but I suspect you may be overinterpreting things a bit. Prosecution and defense present their arguments in court and the jury are supposed to decide which arguments are more persuasive. Even an American lawyer cannot expect the jurors to form opinions while switching their life experiences and knowledge and, indeed, brains off. There is no other basis, and in fact one was originally supposed to be judged "by the jury of one's peers" to make sure that the knowledge and experiences match in determination whether the defendant's behaviour was reasonable or out of line.
What the jury is supposed to "switch off" is any knowledge or perception of facts that were not presented in the courtroom. One major example is media reports. "But there was this article in NYT that said..." must be disregarded during deliberation.
It is not clear to me whether a juror can use his or her specialized knowledge or experience in closed doors debate to convince other jurors. E.g., something that may look convincing to a layman may be disputed by a statistician, etc. I hope it is not disallowed - no reasonable debate would be possible. Jury deliberations will not be about facts but about counting votes. (Are jury decisions supposed to be 12-Angry-Men unanimous?)