The default config src/main/resources/sudachi.json#L23-L24 which is bundled with Sudachi JAR v0.7.3, it passes non-existent property joinKanjiNumeric to the JoinNumericPlugin.java#L56-L59 which in fact uses enableNormalize property.

I guess this is not a huge issue because the default value of if the enableNormalize does not exist is true, which means Kanji numerics get normalized by default

@Override
    public void setUp(Grammar grammar) {
        enableNormalize = settings.getBoolean("enableNormalize", true);
        ...
    }

But, it would be great if this gets fixed in case if someone does not want to normalize.