your plugin looks great, but little details are missing to make it 100% compatible with the Brazilian market. Here in Brazil, we need the Brazilian Market on WooCommerce plugin https://br.wordpress.org/plugins/woocommerce-extra-checkout-fields-for-brazil/ because the gateways and also logistics companies requires different informations.
For example, we have a separate field for the house or apartment number, which is registered by this plugin as billing_number and shipping_number.
There are some other custom fields indispensable for any Brazilian store, which can be checked in the documentation of the Brazilian Market on WooCommerce plugin, but if you just allow us to include custom mappings for the custom fields in "billing options", it has already solved our problem.

