Do you already have a system for non-WK vocab and kanji ? If not when the need arise eventually I would recommend Anki (free but can be a bit tedious to customize to your needs) or JPDB (freemium) or Kitsun (a few € / months).
I personally use JPDB to store all my known vocab and for new words exposure and Kitsun for an easily available typing input for kanji consolidation.
Also looking your new kanji friends and their multiple concepts though https://jisho.org/ will help you differentiate them… (you can add the secondary meanings to ‘user synonyms’ on the WK interface).
Have fun 