Hi, matti here.
Appreciate the feedback. We agree there's definitely more work to be done on exactly how trees are represented to the user.
When I was using twigg to build itself, I often just used the side panel branch off when I needed to instead of using the tree diagram. The tree then kind of built itself.
Would be interested to hear if you prefer having the tree up on screen, or if you prefer the 'branch to the side' approach.