I have not fully explored LabVIEW NXG, but on the first look I have noticed that LabVIEW NXG uses rounded nodes in block diagrams, and wires use sharp corners where they change direction. Visually, I think wires should be rounded and all other nodes on the block diagrams should be rectangular (or left as an option to the developer). SubVI icons are editable by the developer anyway. Wires are like rivers, except they carry data (at least in our minds). Rivers do not change direction at 90 degree sharp corners. In my opinion, it is more intuitive and perhaps easier to understand the code if data wires use rounded corners and other nodes look like solid objects, with any shape chosen. Just a thought.
Declined for reasons listed in post by AristosQueue:
"The visual design of NXG has been extensively tested in front of users across the world for over 8 years. The smallest things, such as roundedness of corners, were evaluated. Even exotic changes, such as non-manhattan wiring (i.e. diagonal and spline wires), were evaluated. The diagram today is where NI believes we get the maximum readability of the diagram. It will not be changing at this late date."