See TIP of the day: Plain meaning/ analytic reading - text flow diagrams for examples of many of the methods and examples.
1. For the text flow/arcing style diagrams, add a function that allows one to auto-align the selected lines. A snap to grid function would also be appreciated. At least for myself, the difficulty in getting things precisely aligned for a polished look is a major reason I use other tools.
2. While one may often want to customize the results, the rules for a mechanical layout text flow diagram is called mechanical because the rules can be automated. (https://seekingourgod.wordpress.com/2015/01/20/a-mechanical-layout-of-scripture/) Please add an automated process to generate mechanical layouts.
3. I may be missing it, but I don't see the vertical arrow used in several forms of text flow diagrams. Review the symbol options for other missing options.
4. Allow one to import the Bible text in multiple formats: (a) lectionary format i.e. sense line, (b) clause format, (c) propositional outline with or without labels (d) discourse analysis with or without labels. I'm sure others will have additional suggestions.
5. For brackets and arcs, support automatic adjustments to keep the layers of brackets distinct with space to include label if appropriate.
6. Microsoft now offers a free English sentence diagrammer that performs its own parsing and Reed-Kellogg diagram. That means it is time for Logos to provide automatic Reed-Kellogg diagrams for unparsed English and for parsed other languages. This would allow one to have side-by-side diagrams of the Hebrew, the LXX, and English (multiple translations even) for study.
7. If possible, allow exporting to Canvas where cards and free-form lines etc. can be added to the sentence diagram.