about:performance reports performance issues

[Gitoffthelawn]

Firefox's about:performance reports that this extension negatively impacts the framerate.

[SW1FT]

There's a reason why they don't show the add-on performance on about:performance from Firefox 56 and above, it's because it's not reliable and essentially flawed. Also, this add-on will probably be discontinued as WebExtensions will become the norm from Firefox 57 and above, so you will need to use the built-in Containers feature.