Hi,
Thanks for the reply and idea.
I should have probably mentioned public portfolio 
So, they create a topic that everyone can see, but they are the only ones who can reply to it. I appreciate that they could just edit their original topic rather than replying to it, but I don’t expect a vast amount of our users would do that, equally, it may be beneficial to have the timestamp that comes with a reply against each update that they make to their portfolio.