So, about a month ago I posted an incredibly griping review of this add-on, having experienced many minor headaches with it. Since then, it looks like the author has busted their butt fixing my complaints and making general QoL improvements. This is now quite simply the best darkening add-on that Firefox has to offer, and blows most other ones I have used, across multiple browsers even, out of the water. Kudos to the author for caring so much about this product, it really shows.