tdj

Yes, I did.

The problem is that this section in the __construct function of the main class is run before any custom filters can be added:

// apply some filters to easily alter the frontend messages
foreach ( $this->filter_vars as $var ) {
	$this->{$var} = apply_filters( 'zeno_report_comments_' . $var, $this->{$var} );
}

You can fix it by moving that into its own function and hooking it on the ‘init’ hook, like this:

public function __construct( $auto_init = true ) {
...
    add_action( 'init', 'zeno_apply_filters' );
...
}

public function zeno_add_filters() {
    // apply some filters to easily alter the frontend messages
    foreach ( $this->filter_vars as $var ) {
	$this->{$var} = apply_filters( 'zeno_report_comments_' . $var, $this->{$var} );
    }
}