[dallamaneni]

Firefox developer edition allows using unsigned webextensions by toggling xpinstall.signatures.required to false in about:config

[bigbugbag]

waterfox allows unsigned extensions.

It seems to me disabling the xpinstall.signatures.required setting has no effect anymore, at least the last time I tried using it, it had no effect.

[vetinari]

Firefox developer edition is the former Aurora (development) channel. It is not the stable release channel.

[johnny22]

You could use the unbranded builds. They build them specifically for your use case. https://wiki.mozilla.org/Add-ons/Extension_Signing#Unbranded...

[dblohm7]

FWIW, developer edition is now the Beta channel.

[the8472]

It's not labeled as stable, that does not mean it is unstable.