Would it be possible to sort the Kanji related words that have a green + or are 'Known' to the top of the list? This might not catch everything if the list is paged, but should get most common things.
An alternate would be icons to manually sort, but I think "Known/Scheduled" should be default.
Another step might be to put a tiny dot (like a blue notification) on the Kanji pronunciation tab title if it contains one I know, to be able to find it at a glance rather than digging into each, especially for Kanji with 4+ pronunciations.
Would be great to extend this better sorting to dictionary search as well.
I'll consider this when I do the kanji overhaul later this year, but it will have to be a setting - a lot of users would prefer the opposite - they look for ones that they have not yet studied so they can add them to a vocab list.