@lcamtuf @fugueish@infosec.exchange

NixOS supports installing Firefox extensions as part of the OS (as in, so that the extensions come from the same build system/package manager as the rest of the OS). It makes use of the fact that you can disable extension signature verification in ESR versions of firefox. https://github.com/NixOS/nixpkgs/blob/master/doc/builders/packages/firefox.section.md describes the thing in more detail.

Sadly, the standard package repository for NixOS doesn't have the extensions themselves (maybe it should?), so one can't benefit from the slower uptake etc.