Moodle HQ has made a lot of progress integrating the UCLA Grade report interface improvements which allow you to scroll large courses more easily when looking at the complete grader report. While this isn’t the only improvement being made to the gradebook at this time, it is one that might have the largest impact from a usability standpoint.
If you’d like to stay up to date on the Epic progress for the gradebook enhancements check out https://tracker.moodle.org/browse/MDL-25544
The Epic is part of the current sprint (project timeline) by the HQ team ending in about a month. Hopefully we’ll see this as part of the major Moodle fall/winter release of 2.8.