I love this extension and have used if for a couple of years.

One oddity is that the extension uses a lot of CPU cycles even when the browser first launches and has no open tabs !!!

In firefox' task manager the extension is consistently the top energy user within the browser (always scores ~20 in the energy impact column - even when nothing is being downloaded and NO TABS ARE OPEN). Hovering over the extension in FF task manager reveals a consistent rate of ~300-~500 dispatches per second, non-stop (again, even when the browser has no open tabs and has just launched)

The issue can be seen from the operating system level ... firefox consumes 5%-10% CPU non-stop. The cpu utilization drops to near-zero the moment I disable this extension.

It isn't a huge problem, but sometimes the extra cpu utilization is just enough to kick in the cpu cooling fans, which are annoying to listen to.

I wonder if the developer can add some sleeps to his code that would avoid the extension from constantly spinning its wheels.

This is on a linux system (linux mint). Not sure if it occurs in Windows' version of firefox.