it would be nice to have a filter that shows kanji that appear in words i know/don’t know in the kanji index. This could help identify kanji i’ve learnt without learning any words using them, or choosing which kanji to learn based on words i know.
This is an interesting idea, thank you! I do not have time to add anything to the Kanji Index at the moment, but I hope to do a revision of both this and the advanced search sometime this year.