Magento 2 Checkout: Apply custom validation only on submission

In Magento CE2.4.5 I have added a custom validation to the STREET field. It needs to be validated if the field contains both text and a number as many customers forget to submit their house number:

'validate-housenumber': [
        function (value) {
            return utils.isEmptyNoTrim(value) || /^[A-Za-z0-9]+[ ]+[A-Za-z0-9]/.test(value);
        },
        $.mage.__('Please enter a house number')
    ],

For testing reasons I have added this code in:

Magento/Ui/view/base/web/js/lib/validation/rule.js

However, the validation happens immediately when starting to type anything in the field. I would need either one of these solutions:

(a) Validation message appears after leaving the field (desired)

(b) Validation message appears after clicking the button to the next checkout step (just like it happens with required fields not being filled out)

Any hint would be very welcome. Thank you for your help!

Alex