Why do you want sliders when a config file would do the same just fine?

It's true that design theory writing is annoyingly verbose and intangible, but that doesn't make it wrong. Give someone a concrete language spec and they will not really know how it feels to use the language, and even once they do experience its use they will not be able to explain that feeling using the language spec. Invariably the language will tend to become intangible and likely very verbose.

But to answer your question: no, it's of course perfectly serviceable to just copy the interface others have created, and if the needs aren't exactly the same you can just put up with the inevitable discomfort from where the original doesn't translate into the copy.