Timeout not working for non-widget instance

I have added the custom timeout function described on the plugin developers page:

function testimonial_rotator_widget_set_timeout( $args ) { return 10000; }
add_filter( 'testimonial_rotator_widget_timeout', 'testimonial_rotator_widget_set_timeout' );

…and indeed this is changing the rotation timeout for when I use it as a widget in a sidebar.

The only problem is that I am also using the plugin called directly in a template file using php:

<?php echo testimonial_rotator( array( 'id' => 301500, 'shuffle' => 1, 'limit' => 10) );?>

In this instance, the rotator is not using the new function (or even default as I have even changed the timeout directly on the plugin php file.

I would love to slow it down a bit as I have some long testimonials for people to read.

Cheers.

https://ww.wp.xz.cn/plugins/testimonial-rotator/