Great concept but the plugin is an absolute memory hog, and they've been unable to fix it.
They closed the old bug for no real reason:
https://github.com/EFForg/https-everywhere/issues/1775
Then let the new bug rot:
https://github.com/EFForg/https-everywhere/issues/12232
They've now started deleting new comments on the new bug. I'm just not using it anymore.