I believe that beginning to distribute tools that patch Firefox and give back power to users and allow them to install unsigned extensions is necessary when an organization is taking away our rights without giving us a compelling reason for doing so.

The other pressing issue is that users have lost the right to run private extensions in the release version of Firefox, without needing to hand over their source code to Mozilla.

I would like to know if you know a way to load unsigned extensions without requiring a developer or unbranded version of Firefox.

To load one temporarily go to about:debugging, "This Firefox" and click "Load temporary add-on from file". More permanently: many (most?) Linux distributions allow unsigned extensions to be placed in /usr/lib/firefox/browser/extensions/ and they will automatically be loaded, provided they have valid names (e.g. dodgy@unsignedextension.com.xpi).