Thank you Ash,
After reading your response and some exploring in the plugin PHP files, I seem to have found a temporary fix.
In the plugin file: adkingpro/includes/admin_area.php
and the function:
function akp_my_scripts_method()
I have commented out the following line at the end:
//wp_enqueue_style(‘akp-dynamic-css’, admin_url(‘admin-ajax.php’).’?action=akp_dynamic_css’);
It seems that my CSS styles are still applied to my akp units, however I no longer see the long wait time on Pingdom for wp-admin/admin-ajax.php?action=akp_dynamic_css&ver=4.2.2
The overall page load speed has also improved significantly.
As I mentioned, my CSS styles in the custom CSS box are still applied to my pages (removed the CSS from the custom box and the styles disappeared, then added them back in and they reappeared).
Have I broken anything that I just won’t notice until later or will this serve as a good temp fix for now?