Freemius SDK

Hi, I am interested in purchasing this plugin and would like to know if it uses Freemius SDK to handle the premium/pro version of the plugin? I have had issues with Freemius glitches in the past with plugins, sometimes it would totally lock users out of the dashboard for a site because it could not verify if the domain was activated through Freemius even though it said it was.

If you do use Freemius, have there been any problems, small or large with your implementation of its SDK?