I understand about the issue with the last message in pre-moderation queue. It is excluded from the template, and this is how the add-on should work.
If it will not be excluded - what to display then? I guess the answer is obvious: the last "opened" message available. But to determine such message, the script should go through ALL messages in a topic, to compare them with the pre-moderation array. It's ok if you have only small amount of messages, let's say 10 or even 20. But as more messages the topic has, as longer the script will work. I think, having more than 50 messages in a topic will mean your website's first page will abnormally slowed down. Specially if you have not just one pre-moderated messages in a topic, but few of them.
So: if you use this add-on in combination with Pre-moderation add-on, either you should have $post_sort option of the "First page news" add-on set to 0, not 1 like it appears by default. That way it will display the first available message in a topic and will sort by new topics, not the last messages (actually, this is how this add-on is supposed to work; setting it being sorted by last messages is really specific and it doesn't mean something "new" anymore).
Or - you should live with the method currently set up, i.e. the message is not displayed and that's all. Yes, the username of the last poster will be displayed in such queue, and there is no way to improve it, except going through all messages in a topic like described above. And like described above, I think, it's better to have just an empty space instead of the actual message posted, else it may take abnormally large time to display a "proper" content.
Actually, this add-on can be set up to display topics/messages from the certain forums, and if you care about the quality of your web page, you should not allow it to display all messages or topics posted, but only messages from the certain forums, where only certain users or moderators are allowed to post content. This is also how this add-on set up on miniBB website - under "News" section, only website stuff is allowed to post new topics, and the add-on is set up to be sorted by new topics.