Works very well with good customization options. Would like an option to add a romanized version with the translation and a button that plays how the word is spoken. Then it would have amazing value for learning a new language.

The best of firefox "Recommended" translation extensions, has good functional, has in-page selection translations and full-page translations, but not full-page in-page translations. Translate Web Pages extension has that function and all this extension's functions. I don't why this extension IS "Recommended" and TWP isn't
Also:
TWP has multiple translation languages and more translation enginesm right at in-page translation popup. TWP has much more settings. TWP can work with NoScript extension and the current extension can't
So I will remove this extension and use TWP instead, because only advantage of this extension is that it allows you to use more recent languages than TWP (TWP allows maximum 3, which is not enough for me)
P.S. Found a minus: actually can't use DeepL in-page translate because it needs DeepL API which needs not just login, but also your post adress and credit card, which don't work at all in several countries including Russia, it was better if it used copying DeepL Translate data from (background) page or (zero transparency) html iframe

Works very well, but can be a little finicky.

It's great, works almost perfectly, the only downside is that I can't use it with the DeepL API, whenever I switch to it and try to translate something I always get this message"Error: Authentication of DeepL API failed. Please set the authentication key and plan correctly on the settings page."

Add-on works and is simple to use but I wish there was like a small pop-up or button to switch the output language. As a multi-lingual person, sometimes it's helpful to see translation of several languages to better understand the words.

It does everything I would want an extension to do, but causes an unexpectedly heavy load when opening each page.

The extension is very good: it does its job correctly, and the translations are almost accurate, as well as natural. It would be great if, among the many options, one could also add the ability to translate typed text without having to switch applications.