I would probably add vocabularies in two ways.
Probably anyone can add, as I made every level a Wiki.
Really wish this one was on WK! Got very confused when I met it in the wild, that 天 could have another reading. I feel like it’s a common enough word that it’s worth teaching too, seeing as all the planets are already taught.
Image radicals might be particularly interesting to suggest more. Copied from here – A list of kanji with common components that aren't Wanikani radicals
Horns on the heaven
Open box of concerns
Rice on the lion
Wolverine on the stool
Drunkard holding a cross
Suitable flowery crown
Sun over spikes
I have a scooter
Renamed Kanji / printable characters
Tool of the slave