One thing after years of using ELGG that has made me frustrated is that when you post/edit/delete comments from a dicussion in an elgg group that it doesn't stay on the page that the chagne happened. Example if I have 4 pages of comments and I edit a comment and hit save, ElGG jumps back to the start of the topic.

Simply changing the existing forwards at the end of the files here groups/actions/forums to be replaced by

  forward($_SERVER['HTTP_REFERER']);

Fixed this and makes dealing with large dicussions much nicer.