Hi @janmazanek we’ll take a closer look at this right away. For the RSS triggers, I want to confirm that we do use the is_feed() function to then add the image only when the current request is for the RSS feed itself, none of that code should be running on non-feed page requests. We also use appropriate actions and such as well. There is some code that runs on admin pages, but we also evaluate if the admin page is our own admin page before running it. There may be some licensing SDK code that handles licensing with the Premium version, and performs external requests, but it should not be running with the free version, and it should cache those requests so they are not running on every page request.
Note that we have very large sites with page caching in place using our plugin and they experience no performance issues, so it may also be other plugins, plugin or theme conflicts, or the unique structure of your site causing the plugin to have some issues that affect performance.
I will do more profiling and see if I can spot what code would be causing any time during a normal page request.