WooCommerce Character Limit Stupidity

You can add a function to pretty much customize any checkout field, but not so much on custom product detail fields.

This is the best product to accomplish custom product fields. But I also refuse to pay for stuff.
https://woocommerce.com/products/product-add-ons/

So my go to that works out of the box is this.
https://wordpress.org/plugins/woo-custom-product-addons/