Sounds exciting! I did like the idea of having a line tool though. Aside from its uses in visually connecting nodes, and firing off trigger signals, it makes it very easy to divide chunks of the planning board into their own little areas. Being able to draw lines wherever you want on the board is super versatile.
In the case of something like a literal graph, the ability for a single line to have multiple segments would be really useful. Or perhaps a dedicated Graph node that lets you easily organize information like this.
