removed this add-on because I started getting Fake iPhone X for a $1 scam pop-ups in the Firefox browser.

It is difficult to create an algorythm that would give the optimum result to every page on the net I imagine. That is why respect for the undertaking, thanks for delivery. The addon would greatly benefit from an integrated user feedback feature that just reports which site is with which mode is not working to arrive at an overview.

works but too slow, 10 seconds to show a web page?!?!

There are a lot of little bugs. Sometimes, I have to switch the extension off and on before it loads a side. Sometimes, when I add a site to my exceptions list it renders it as "dark" anyway. A lot of major sites (such as google.com) have parts of UI become invisible with this plug-in active (at least in dark mode). Kinda neat, but not up to the Chrome version yet.

Dark Mode - an extension I've been trying in this one's stead has a much smaller feature set but works far more reliably.

The only thing that would make this extension perfect for me is if your site lists could be synced across browser installations. Is it possible for extensions to use firefox sync?

Спасибо, очень удобно.