When you tap the new posts button, the system should, show the new posts in cronological order but should show the first post and maybe 3-4 of the last posts made on that thread.
This would look like Facebook news feed. With a like button for each of the posts shown.
This should be per user configurable.
This would be a good combination of forums in the old school way of organisation and the new social news feed way. Allowing drive by posts and likes. The reply box should expand when the user taps into it.
Please like this post or if you have any questions to smooth out this idea please ask below!