Hi @webstpro,
Thanks for your feedback. I would have preferred if you created a support request (https://wordpress.org/support/plugin/wp-custom-admin-interface/) for this so I could help you with the issue. The settings should actually take place immediately, so maybe there’s something going wrong on your specific install.
So please do consider creating a support request so I can try and help you with this, and do consider being kind to an independent developer providing a free plugin and updating your review in kind 🙂
Thanks @webstpro