I propose adding the simple package speedrect <https://github.com/jdtsmith/speedrect> to ELPA.  Speedrect is a modal interface that comes alive when rectangle-mark-mode is active.  It provides easy access to enhanced rectangle functionality.  Beyond all the normal (and a few hidden) rectangle functions, some additional speedrect capabilities of note include:

- auto-restarting (so you can easily chain multiple rectangle actions)
- autosave and restore of the last rectangle
- rectangular text wrapping
- robust integration with calc
- quick placement of multiple-cursors