I second what @luchoster is asking.
Without directly modifying the plugin I don’t see how I can access $parameters.
This is a z-index issue.
Add this to your functions.php
add_action(‘admin_head’,’mce_show_dropdown_fix’);
function mce_show_dropdown_fix(){
print “<style>.mce-floatpanel { z-index: 100101 !important; }</style>”;
}