I take this back actually. Just having firejail installed worsens the security of your system due to it being setuid root. I think Whonix should take more of an effort to move away from firejail. It has far too large attack surface and is recommended against by many security experts. For example just look at oss-sec: Re: Re: Firejail local root exploit where a guy found numerous security vulnerabilities pretty easily or look at the CVEs.