Not all adults have that capacity.

If you don't mind, could you give some examples of what conditions interfere with what parts of that process, whilst preserving the capacity to otherwise engage productively on HN?

I think people with learning disabilities and people who do not understand the tone they are expressing over the internet can still contribute positively to conversations, they just need a little bit of grace.

Given the limitations described, what accommodations or "grace" do you propose?

I've already outlined that: clear expectations & when someone does something wrong, but otherwise seems to behave in good faith, explanations.