WooCommerce

As explained at https://wordpress.org/support/topic/how-to-customize-the-required-field-text-in-the-new-block-checkout/#post-18640435, the inline validation message (Please enter a valid %s) for default and additional fields is baked into the Javascript. There should be an accessible way to change this text that appears below a field before clicking Place Order and seeing the PHP-derived Woo notices. Unless we resort to MutationObserver, setInterval, or modifying wc-cart-checkout-base-frontend.js directly, it seems that using a CSS hack is our only option.