I am having the exact same issue. This is the only plugin that is showing up on Google PageSpeed Insights as slowing my website down. According to Google this plugin contains a “blocking CSS resource which may be causing a delay in rendering your page”.
I also would like to have “a native css-file which can be minified so that less requests are required for the website.”
Looking forward to your next plugin update…hope to see this change in the release notes ??