Currently the forum will only indent have 4 levels of indention for threads. If there are multiple branches of replies, it can really be difficult to see which reply is replying to which another reply.
If we can add more margin to the replies on deepest level of tree, maybe it can be easier to tell.
Of course, it would be even better if we can add a button to each reply box to "highlight all parents" so we can see the chain of replies that's related to the selected one.