@nmiletic thank you for reporting a potential issue with the plugin. After all, it’s a performance one and its main purpose is to help you out with the optimization and not use many resources. Without a more details report, it’s hard to say why the number of calls is so high. I know New Relic can determine what parts of the plugin (e.g. method within a class) are using more resources then others and I believe you need to check that. Without more details, it’s hard to say why the number from your chart is so high. The plugin is called indeed whenever a non-cached page is accessed.
If you were using a plugin such as WP Rocket, Asset CleanUp as well as other plugins would not have been called so many times as the caching plugin would serve the static HTML pages without triggering any plugins’ PHP code which includes queries to the database (some of those query could be using lots of resources).
Let me know if you can provide me more details about the resources used via New Relic. Meanwhile, consider setting up a caching plugin (or perhaps your hosting company has a caching system that could be activated). Your TTFB (time to the first byte) in my tests is very high (~3s, sometimes 5s) and that would be the first thing I would be worried about when it comes to performance. Basically, sometimes, a visitor has to wait for a few seconds until the first byte is downloaded by the browser and at least half a second until they will see content loaded.
