While you are always free to make your own choices, this is very bad advice for someone looking to try another distro.
wiki.debian.org/DontBreakDebian#Don.27t_make_a_Fr…Official documentation again does not recommend mixing multiple releases like this. You would be much better off just running Sid, or Stable then using the Firefox flatpak/snap/appimage for the latest release. Debian is a long term stable distro, so if you want newer packages you are advised by the developers of said distro to just use Sid.