I feel like there should be an option where you can pull up kanji and radicals side-by-side so you can analyze the small details between them. I’ve noticed I get the same ones wrong over and over because I mix them up. And usually it boils down to the end where it’s just those left in the review and they come up one after the other. And that’s usually when I can actually spot the difference is from seeing them quickly next to each other.
I agree. There is currently a user script that does similar things however! The confusionguesser superscript by @Sinyaven
There’s also a visually similar kanji script, which I find pretty useful. Maybe it helps!
Writing the kanji can help with this, as you tend to remember the small details this way. Also writing it in a word and writing the word in a sentence can help too.