I would like to say that this does beat out the other about:config option modification add-ons, but all these type of add-ons are missing an option to add my own toggle. You see I need to toggle various options to test out web pages and report back on their compatibility with FF. I am not a developer, only a tester. But I need to toggle things like "security.fileuri.strict_origin_policy", and other such obscure items. Rather than bugging the developer of this extension to create a new toggle every time someone needs a new one, can't there be a entry box for the config item, then two more boxes for what it is supposed to be when you toggle it on and off? Maybe add these as a list of items and they show up on a special page called "Custom".