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