IMHO there is nothing wrong with the N word used in an history lesson.

Have you spoken to any [other] people that have been subjected to anti-black bigotry directly about how its inclusion would affect them in a lesson?

I am a white man that had a similar view to you. About 10 years ago I had a conversation with a black classmate about appropriate use of that word. It was my position that it's too bad we continually empower the word by avoiding it even in dry intellectual contexts and we shouldn't censor it when reading quotations.

She said:

I know you're not being racist but it still makes me super uncomfortable to hear you say it.

I made the decision not to say it ever again. Obviously my classmate can't speak for all black people, every person has different experiences, and reactions will be along a continuum. There might be situations where the educational value of using that word explicitly, outweighs the discomfort it causes. But I think it's pretty inappropriate for me to 'whitesplain' prejudice (and the language of prejudice, and the power... of the language of prejudice)

Teachers have to ask themselves: How much will its explicit use enhance the lesson? How many students are we willing to risk alienating? How much time would we like to spend defending our decision to use the word explicitly? How much of that will be class time?

Even with a lengthy preamble setting the perfect context to use it explicitly with minimal potential for alienating students there's a significant chance we'll fuck it up and spend the rest of the class reteaching the class why we think they are wrong to be offended.

Some of them will be disingenuous, some of them will be sincerely offended white soyboys not too dissimilar to me, some of them will be legitimately alienated racialized minorities.

We'd also be implicitly asking the non offended racialized minorities to stick up for us. Their well meaning friends will ask them to weigh in on the subject (and speak for all blacks). It's not fair to them.

In a context where class time is limited, I have to think that students are best served with more lesson time and less meta-discussion. So I don't think it's a good idea to use the word explicitly in educational contexts, unless maybe there's some sort of vetting of students for the course.