Save PayPal Payer information in Order Metadata
When a user pays with PayPal, the PayPal email, first name and last name are not saved as part of the order metadata. Since the these values may be different than the values for the logged in user they should be saved as part of the order metadata. This payer data is sent back in IPN response.
There is also no way to customize the code to handle this as there are no hooks in the WooCommerce code for this: woocommerce\includes\gateways\paypal\includes\class-wc-gateway-paypal-ipn-handler.php.