When I was in law school nullification was only mentioned in passing, as a matter of history.
Probably because it would readily result in disbarment of attorneys that found it too interesting.
Jury nullification essentially flies in the face of the orderly established application of settled law, and few people that make law their career want people just ignoring all the principles, case law, and other aspects their education and career is based around.
The result is few judges will even tolerate the mention of it in a court room at all, and a prosecutor most certainly would take every step possible to get a new trial if it is openly mentioned in the court room.
Nullification has little chance for a large number of reasons. First it requires people to even know about it. Most people do not.
It is often career ended for an attorney to advise a jury of nullification. So it won't be the defense attorney specifically advising jurors about it, how it is historically and constitutionally acceptable, or why it can be used in direct conflict with the jury instructions given by the judge.
No judge is going to tolerate it being used to undermine their instructions in a court room and make decisions contrary to the law.
An attorney will quickly find themselves disbarred that informs juries about nullification.
Finally judges often declare a mistrial if it becomes obvious jury nullification is playing an admitted role in the outcome of a case.
If you get a mistrial because it became obvious jury nullification would play a role, the whole concept fails to work because more decisions based on jury nullification will be undone, while more of the opposing decisions will be allowed to stand having been decided in accordance with the law and legal instructions.
So jury nullification essentially requires people to already know something they cannot talk about in court, nor can prosecution nor defense inform them of, and which a judge won't tolerate.
If declared by a juror the principles of the juror become moot because they will be removed or a mistrial declared and a new jury without someone with such principles will be brought in to make the desired decision.
If a new trial is held and the person is convicted anyways, the beliefs of that jury member didn't really matter in the end, and their principles just resulted in someone without those principles making the decision anyways.
So it requires the jury member to often remain silent on their reason not to find someone guilty, and never mention the word "nullification".
All of this makes a realistic campaign of reliable nullification that actually results in regularly completed cases that make a difference difficult to achieve.