Thanks @Sailsman63 and @sam.
I have since found out the user is using JAWS 15 but is in the process of upgrading to 17 which hopefully brings some improvements.
I have advised about the “email me for every new message” setting and I am in the process of getting a replies@ inbox for the incoming email.
I have also informed the user of the keyboard shortcuts for navigating around the forum. I noticed that when using j and k to select topics and posts a selected class is added to the selected item. As we are not using the browsers focus state, I would guess that a screen reader would not pick that up. If there is a reason we can’t use focus, maybe aria-selected is appropriate here, although focus is probably ideal?
Relevant: ARIA - Managing Focus
I will install a JAWS 17 trial and try to provide some concrete feedback.