According to Understanding FiddlerScript, if you don't define Rules=>Customize Rules, then Fiddler uses "the latest SampleRules.js file included in the Fiddler installation package".
But what if I want to add define just one specific rule and still always enjoy the latest SampleRules?
Is it possible to use customized rules in an opt-in fashion? That is, keeping customized rules almost empty and having all defaults automatically be loaded from SampleRules?