I though it might be nice to have something like the following features added to the kanji index:
1. In addition to the options to filter known/unknown and studied/unstudied, it would be cool if there was an option to filter kanji by whether or not they appear in any vocabulary in the dictionary. For example, the Kanji Kentei level 1 index is extremely large, but most of the kanji in it have no attached vocab. I would love it if I could filter those out and get an index showing only kanji that have vocabulary in the dictionary.
2. Currently you can generate an index from a kanji mastery schedule, but something else that would be useful would be a way to generate an index of kanji that appear in the terms in a vocab mastery schedule. It would be helpful in finding kanji that are used in my vocab schedules but that I haven't studied on the site yet.