Replies in nested list in maillist mode

One of our accessibility users (poor eyesight) who used the maillist mode had this in mind:

“That is, it seems we’ve managed to successfully read the text, comment on it, and create new posts - that’s true. The only part missing, which I’ve already discussed with Joakim but don’t know who might do something about it, is that when I’m reading a reply, the replies should be inside nested lists, so that I know whether I’m reading a reply to a top-level message, or a reply to a message one level lower, or a reply to a reply to a reply, and so on.”

Anything I can tell him about this?

Yes I would recommend looking at this setting:

Perhaps the user should set it to “never” to avoid getting confused.