None that I can think of that I could implement from this end. It's important that reading the last message trigger resetting of the number of unread messages.
But my personal approach is that I'll do one of the following:
1. If I want to respond to a post that is a long ways from the end, I'll right-click the Reply link, and reply to it in a new window so I can continue forward in the original window.
or
2. After submitting the post, hit the "Back" button twice to go back where I was.