The tree view for the boards is great, but it gets hard to read when the conversations get long. This means that the longer a conversation gets, the harder it is to contribute.

 
The solution? More indents, background color changes, and the ability to collapse the tree under a given post.

I'm talking about something more like this: http://i.imgur.com/aXRWj3z.png

 
Which with a little collapsing magic can become this: http://i.imgur.com/BsG2FGY.png

 
This allows posts further down the chain to be read in context with the post they were replying to. This solves a major readability problem when reading a post that has a ton of replies.

 The color coding is per tree level. So the first post is white, replies to it are light grey, replies to those replies are back to white again. This generally helps with following a thread because it's easier to tell which level a post belongs to.