Hi Neil,
I can't get it to start at all. The instructions for installing from .zip are not sufficient.
If you pull that *.7z archive you will find that the contents follow the RPM package directory structure, makes sense since they built it from the RPM package itself...so if you are like me and are looking for the old layout you will have to move the stuff around manually. That is pretty simple though, just move the stuff from unzip_path\@unix_root\usr\lib\firefox... to your final destination, in my case that mapped to g:\apps\tcpip\firefox
Also, make sure you review the contents of the RPM_REQUIREMENTS in the main unzip_path location. I found at least a couple of RPM packages there which I previously did not have or had an outdated version (and yet I was able to successfully test the pre-release versions):
1) bww-resources-rpm
2) hunspell
...and certainly there is a DEV version listed of the RPM package libc-devel, which you probably do not want to install since that contains a pile of source code...but again, just my experience here, I did not install it, FF 45.9 is up and running fine here.