Yeah the Duration had to be different because MineTweakered Recipes will ALSO use that Config File, so the Recipes you add might also instantly be disabled with that same Config, luckily the Default Value is always part of the Name of the Config.
Oh btw, in the next Version some Shredder Recipes will be cheaper, this may change the default value of some Config Lines and therefore technically their Name. Just making sure you double check the Configs after that Update.