Neat. Turns out that https://addons.mozilla.org/en-US/firefox/addon/enterprise-policy-generator/ is a pretty nice frontend for generating configuration to feed to https://mozilla.github.io/policy-templates/
Why would you want to? Because it allows you to force load from the side a set of preferences and extensions. For your own use, or give to others.
Also, works great for #QubesOS #DispVM config where the VM gets recreated every time 馃槀