using the after_shortcode parameter

Hello,
I love this plugin, and am using it to display the rp’s after the content using the filter. I’d like to display a button after the rp’s, and thought I could use “after_shortcode” to wrap the button code in. I tried wrapping it a couple of ways, escaping double quotes in the html, etc, but it’s not showing up. Anyone else using this for more html than </div> ? I guess I can add it to a variable and add it that way, or find another hook, but I’m curious as to how it would work with more complex stuff. Thanks if anyone has done this!