CSS in JS Tools cause style tags to rerender on change

I’m using Free-Style to render CSS on my site. However, with the developer tools open, any change to a style tag causes the styles to be redrawn, causing jitteriness and flashing content. It doesn’t happen when browsing with the developer tools closed, so I’m guessing it’s related to how the inspector works with updated styles.

The same issue is not present in any other browser.