I love diagramming text in a variety of ways, much more than heavy highlighting. But I also have the misfortune of having very very poor hand-eye coordination so the manual effort to keep things straight, aligned, aesthetically acceptable is a challenge ... one that is very, very time consuming for me to achieve in the Sentence diagrammer. I might be a bit more patient if I hadn't been able to do this for free for more than a decade.

See how I simply add a few brackets and tags and a tree diagram magically appears?
What do I think the sentence diagrammer should do?
Tree diagrams: It should have legends of available tags for all the visualizations included in Logos/Verbum so that I can try to build the diagrams myself rather than simply nodding my head at various analyses given. It should have (or allow users to build and share) legends for both constituency and dependency grammars. It should auto-build from the standard bracket notation. Multiple orientations are necessary.
Kellog-Reed diagrams: These are pedagogical diagrams for subject-verb-object languages. I am not familiar with more automated versions of these diagrams so the current tool may still be acceptable.
Lector's sense-line reading guides: These divide the text into sense lines and use marking up to indicate emphasis, speed, and other oral aspects to help the lector proclaim the Word. When an actual lectionary divided into sense lines is available in Logos, it's text should be available to use as the Bible text.
Text flow/mechanical layout: It is probable that the basic diagram could be automated with the user only tweaking the results. At the very least, the alignments could be automated to a select-and-align approach.
Arcing/Bracketing layout: Here again, legends of possible values and automatic placement of arcs/brackets would be greatly helpful



Dependency sentence graph: This is a lesser known diagram that works well in small groups as it is very intuitive to read and simple to build on the fly. A select 2 words - connect with (or without) operator with automatic placement of arcs is very feasible

One could make a case that the box format of Open Text should be supported or that Outlines belong to this tool. What do you use that I haven't covered, especially non-English tools?
Suggestions:
EDIT: I should have considered Propositional Outlines and Discourse Analysis here as well - both as legends to attempt dividing and tagging the text ourselves but also to apply other theories of Discourse Analysis. Chiasm, concentric pattern, stairstep pattern, and parallelisms are other graphic textual analysis that fit into the same framework.