Practical, especially if you want to upload something from your PC to Instagram. Even now, when I want to use Teams in the browser, I can do so despite Microsoft's disabling, because I pretend to be on Edge. I noticed that the Chromium-based Edge is still missing and only the old one is available.

where is white list/black list domains? so, its only full switching for all sites?

GUI awesome, but ...(

Good

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."