Those fields are for passing variables, not values, and they only apply to plugins using the old (pre-v4) plugin interface.
This plugin can check variable values directly, so if you want to override a setting, use the appropriate VoiceAttack action to set the given variable to the desired value (as mentioned in the documentation for the plugin, the setting you are attempting to change would use a Boolean variable) anywhere within your profile, and the plugin will apply that setting instead.
This also means that the variable value doesn't need to be set with every plugin execution (assuming you want to keep the setting, of course).
Do note that once you set a variable value, due to this plugin using globally-scoped variables, the value will remain set for the duration of the session (I.E. until you close VoiceAttack).
If you're using this plugin in multiple profiles, you'd likely want to assign a command to the "Execute a command each time this profile is unloaded" option containing the action(s) to clear those variable values.