I’d recommend the ConfusionGuesser script. When you get a review wrong, it guesses what other items you confused it w/ so that you can study the differences between two kanji.
native content/reading works, but it’ll probably probably take a while to run into those specific kanji.
I also made an app that creates short stories using your WaniKani items (requires a WaniKani api token). Anything you look up while reading gets repeated in later stories until you stop needing to look it up, so you can somewhat drill seeing them “in the wild”.
It’s not smart enough to know which words you mix up though, so you’d have to search for those and add them to your deck yourself if you want it to focus on exposure to those ones.