This is generally how I first approach writing tests, however, there is a danger lurking here - sometimes these properties will be coupled in ways that are not

This is generally how I first approach writing tests, however, there is a danger lurking here - sometimes these properties will be coupled in ways that are not immediately obvious and your tests will not catch it, occasionally causing weird problems elsewhere in the stack. Of course, you can always just add more tests after you uncover that, but this is always my deepest fear when approaching it in this manner. This is also a relatively binary/simple case - off/on. Business logic is frequently much more complicated than that.