I've never used that one. Why did you go directly to a paid plugin or this specific one, if I may ask? There are a number of free plugins (many with the option of additional features in a pro version) listed at WordPress.org, including the Yoast SEO plugin which does several other things to help with SEO on WP sites:
https://en-ca.wordpress.org/plugins/search/schema/
For me, the benefit of using plugins, free or paid, is
- WordPress.org vets their plugins for compatibility and security vulnerabilities and will remove any that do not comply with their standards; and
- You get access to reviews from real world people using the plugin on real libe WP sites.
For those reasons, I would always recommend that you use plugins listed at WordPress.org.
Note: you probably shouldn't be running a standalone schema plugin if you have another one installed that already adds that feature.