Good but he needs some improvements

You should have a select list with the “default” status of the order after payment succeeds!
Every time I need to make changes in: wc-netopiapayments-gateway.php at the line 480.
from
$order->update_status( 'completed', 'Payment received, your order is currently being processed.' );
in
$order->update_status( 'processing', 'Payment received, your order is currently being processed.' );

There are invoices plugins that generate the invoice automatically after the status “completed” and that’s not good.