Comment by efskap
3 hours ago
>Firefox doesn't allow you to bypass its marketplace and load extensions that you build from source yourself
It's less than ideal but you can 1) load extensions temporarily in about:debugging, 2) turn off xpinstall.signatures.required in nightly or dev edition to install them for good or 3) sign on addons.mozilla.org without publishing to the marketplace.
Or 4) patch the checks out yourself. As they say, "Firefox is open-source for a reason."