but dig a little deeper and you'd realize that many people labelled as "holocaust deniers" just questioned some specific numbers and concepts. some did original research on the matter, some presented evidence to support their case.

Are you talking about David Irving? He would be the only one who would fit this bill here. And yet he has an obvious agenda, which is the praise of Hitler and taking down of people like Churchill. You may want to read Evans' book on the trial.

even if (as I believe) most of the official narrative about the holocaust is correct

What exactly is the "official" narrative? As far as I know, there is no "official" narrative.

do you seriously think there are no accidental inaccuracies? no intentional fabrications? based on just what you've seen since 2020, do you really trust the official narrative, on anything?

It's been quite a long time. Fabricatons have come along and been exposed, like the Hitler Diaries and WIlkomirski. As for accidental inaccuracies. No one's called a denier by anyone serious who exposes such an accidental inaccuracy.

and in this very thread you just dismissed a large group of people who range from genuine scumbags to the simply curious to unpopular researchers who are operating in good faith, as "idiots who deny atrocities".

Do you have several of those unpopular researchers on hand? I think you grossly overestimate the good faith in which they operate. Irving is the best among them, but even he is nothing to write home about. (Obviously, he should not be prosecuted, let alone jailed, either.)