the browser is now reflected as firefox 56 and google drive/site are complaining : not supported. after disable, it shows again firefox 92

I just tested your extension with this site: https://www.deviceinfo.me/ and surprise it's not that good.
Here is the response from the site "Supports real browser kernel detection even if the browser is spoofed, for: Firefox, Chrome, Edge, Internet Explorer, Safari, Opera, Konqueror."

Works wonderfully, would recomend.

Let me download Windows ISO with ease

Does what it is intended. However, I would prefer if the user agent selection is somehow limited only to the tab where it was selected.

If you are like me and just want a SIMPLE user agent switcher for a few sites, this is the one. Just go to the site you want to use, click on addon icon, "override for domain", select a link variation and you are done. I use it mainly on instagram desktop and I have tried 2 different similar addons before and they either didnt work, or were too complicated. I figured this one out in 2 seconds literally.

It's very easy to use.

Works very well but the user agents have outdated browser versions.