Unfortunately that’s not possible without a decent amount of coding right now.
This plugin is brand new (0.1), so I’ll be adding more features to it as it grows older. I’ll definitely consider creating a shortcode that you could choose to have on the edge of the screen like my contact form.
I’m using Contact Form 7 for the actual form, and some custom coding for the overlay effect. I can point you to a tutorial on creating the overlay – however you may be better off searching for some “lightbox” WordPress plugins.