@dax, @codinghorror, I found out why the link counter was working for me and others on our forum. In _Preferences/Interface/Other, although I did have the Open all external links in another tab checked, I also had the Show counts on browser icon checked. Apparently the latter overrides the first box. I unchecked the Show counts on browser icon, saved, then checked a post… the counter showed up!
I also found one little nuance. When a user posts a link and OneBox tries and fails to OneBox it - leaving the link as is - the link click counter will not work if the link isn’t preceded with a blank space. I just edited a user’s post where this just occurred, adding the space, and the counter began showing. 