I am kinda in the middle with this because it adds clutter to the node you are looking at.
I disagree, I don't think a link will be any kind of clutter. It is, however, a difficult thing to determine. Each message is a child of a parent node, and that parent node need not be a message node. I haven't looked at the E2 code, but node-based messagebases usually take a huge hit if they have to recurse up the tree to determine their parent-of-parents.