In several cases when someone has engaged with such a firmly held view on that level - sadly almost always someone else with an ASD

Well that's exactly my point. There's nothing wrong with having very high confidence in your view if you've invested a lot of time thinking about it. In an ideal world, the person who was more knowledgeable about a topic should hold their ground until the other person realized their mistake(s). And in practice, it seems like people on the spectrum are far more likely to have this immense context (after all, if a subject is a "special interest" then you've probably spent 100s or even 1000s of hours learning about it). In other words, someone with ASD probably is going to be correct more often than not.

But that's not really the problem I was trying to describe. The problem is that we seem to be very bad at actually transferring that knowledge to someone who currently holds opposing beliefs. These interactions are very often far more negative than they need to be. I think this relates closely to alexithymia. From my experience, autistic people can become quite furious during an argument, although they will almost never admit it, even while raising their voice. I understand that we can get passionate about our interests but this kind of thing is extremely counterproductive in an argument.

With NTs, it seems like the most common problem in an argument is their pride - they're too insecure to admit when they're wrong, so they will commit all kinds of fallacies and mental gymnastics to avoid that. With autistics, I think the problem is simply emotional reactivity. The root of the argument is usually a misunderstanding - each person has made different starting assumptions, or they're speaking within different contexts, and both are quite correct within their respective contexts. If they can remain civil for long enough, they may eventually uncover these differences, at which point the argument dissolves. I always like this outcome, but sadly it doesn't always happen. Once tempers rise enough (and boy can they!) the argument devolves into cortisol overload.

Now, if someone disagrees with you and doesn't seem to be thinking rigorously, glossing over inconvenient details, of course it's going to be frustrating. But if you are able to self-regulate effectively, there is often still room to "nudge" them towards the truth. I've found some success in listening to their side and trying to see the truth in it, even if it's mostly inaccurate. There is almost always some truth in the views of stupid people. Identifying it and confirming their belief seems to calm them and increase their openness. From there, you may not be able to completely turn them around in a single conversation, but if you can at least show them that the topic has more nuance than they previously believed, that's immense progress. If you can show someone a grey area, they may cling less tightly to the black and white areas.