Just a little idea I had first thing this morning as I awoke. Splitting first page marked read and unread posts, with an option to enable or disable the feature.

Regards

It would probably be better to just add a filter to show unread or marked read posts rather than screwing up the design

That would be equally effective as long as the option to enable or disable is simple. Rather, it's best that they are on the same page and don't need a page refresh to switch between multiple options. Essentially, the purpose of splitting them up is to keep them on the same pages that you are browsing with the topics you've frequented or have not yet explored being immediately discernible which would save time for both users and staff alike.

Admittedly, the example isn't quite attractive, but I supposed that the idea is worth exploring.