Great mod!

If anyone else is using Fast and Easy Checkout with COWOA enabled, there's a teeny change that has to be applied to /includes/modules/pages/back_in_stock_notifications_subscribe/header.php (line 145) so that COWOA accounts don't get flagged as having an account:

Change
Code:
customers_email_address = '" . zen_db_prepare_input($email_address) . "';";
to
Code:
customers_email_address = '" . zen_db_prepare_input($email_address) . "' AND COWOA_account = 0;";