I really like the “visually similar kanji” feature and I often find it useful. That said, I would love WK to be little … stricter about the similarity.
Half of those aren’t visually similar if we don’t set a really low bar (at which point the feature becomes quite pointless…). In fact I’m not sure I’d leave anything other than parent there. I don’t think sharing a radical is a particularly good criterion.
What I really want is the option to add my own “visually similar kanji” rather than relying on the app. Vanilla WK often doesn’t list the kanji I get confused by as “visually similar”, but the “visually similar kanji” userscript lists SO MANY similar kanji that it’s nearly useless
WK could datamine incorrect answers to determine visually similar kanji. Would be a cool database they could share back with the larger Japanese community.