While the manual aspect is annoying, the inability to show the majority of different chord shapes that guitarists actually use is the show-stopper.
In a perfect world Steinberg would re-do all of their chord stuff. These diagrams should be integrated with the Chord Track and all elements should allow the ability to add user defined chords, voicings, diagrams, and scaqles. Imagine being able to show Chord Track chords in the score, like you can now, but also having the ability to display it as a name (like now), a diagram, or both - and the chord could be anything from a vanilla C major to the nastiest cluster of notes that someone can come up with.
The shame is that the framework is already there to make this work great, but the developers keep stopping just short of making that possible.