The extra windows and forms used by the plugin are a bit clunky. It would be ideal if the main entry editing form had a new tab for configuration.
There are some events that are raised when a new password entry form is shown. By handling these events a reference to the form can be obtained and thus form elements like the tab page can be obtained as well. Use this ability to integrate the form into the main entry form rather than create a new one in the context menu.