$ cat /etc/firefox/syspref.js
// This file can be used to configure global preferences for Firefox
// Example: Homepage
//pref("browser.startup.homepage", "http://www.weebls-stuff.com/wab/");
pref("general.smoothScroll",false);
pref("general.autoScroll",true);
pref("browser.search.suggest.enabled",false);
pref("browser.ctrlTab.recentlyUsedOrder",false);
pref("browser.startup.page", 3); //http://kb.mozillazine.org/Browser.startup.page
I am not at all interested in a host system level change because a system package can just as easily overwrite my changes there. That occurs frequently enough with other packages (eg, GNOME).
However, I think this is useful information to put into the Dockerfile and make that the system level changes. Thanks!
You can override these at the "system" level.