We have implemented the plugin and noticed that PHPMailer is used for mail delivery. Some mails haven't gone out for customers. Plugins should use the wp_mail function for outbound mail. In our case we use AWS SES for mail delivery and have a plugin which overrides the wp_mail implementation. Membership Pro doesn't pick up any of these changes!
Also. It would be extremely helpful if there was a basic widget or shortcode that could be used to render an account login/menu in the sidebar.