Changing the default behaviour of pinned topics

By default topics are pinned until users scroll to the end of lists of topics, then the pin is removed and the topic will slowly descend the list of topics unless it is updated.

We can change the default so that pinned topics stay at the top, but users can choose to unpin them. This would mean “mailing list” style posts would remain a the top a category unless unpinned on a per user basis

I’m inclined to change the default to this behaviour, but interested in what others think.