Do you use Salt Formulas?
In my experience, other people's formula's just can't typically be dropped in, given a little pillar and they're good to go. They're not going to be setup to do exactly what you want them to do, and then they're also going to be setup to do more than you want them to do and add a lot more configuration than you actually need.
They can be great examples, but I'd prefer to start from scratch and configure what actually makes sense in my environment.
Now, breaking my own config out into separate Salt 'formulas', I can foresee a use case where that will be handy for testing purposes. Isolating it so it is easier to use test kitchen or whatever else to just test changes to the formula.