I fall somewhere on the AuAHD side of things. For me two issues arise. It can take me a few minutes to hours to really feel something for complex emotions, then a day or two to let it pass. Some more basic emotions like irritation/overstimulation can be felt immediately, before I even get a chance to think about it.
I also can experience issues where a fixation becomes and emotional anchor and I have trouble processing other events emotionally. Sometimes it's kind of a coping mechanism
Yes, the privileged ones, who had a decent upbringing despite them being a minority, whose parents fetishise concentration camps. Or those with ND parents of course.
Always sucks when I get really angry/frustrated about something even though I know I shouldn't be. Like watching a dumb friend try to break a bottle with his forehead and not being able to stop him
At the very least, being unable to regulate emotions when under stress. Often with the stress threshold and sources being meaningfully different from neurotypicals.
But I think a lot of people miss this distinction, both coming and going. If you can't or haven't identified your stressors, it can feel random. If you are always exposed to your stressors, it can feel perpetual.