Hi @codinghorror,
I have a user who has eagerly adopted the Ignore option, and reports the following:
I had to un-ignore [username] because there’s a bug. As long as [username] is the last person to respond to a thread, that thread will forever show as unread, no many how many times I go into it. Apparently because the system isn’t showing me his message, it just lingers as unread and I couldn’t find any way to manually force it to show read.