I would use the notifier. I don't know why you'd need to use both. A local variable can work. But you have to be careful about race conditions. Generally, race conditions are more of a problem when you might have multiple writers. Or if you want to pass all the data along without losing any data, or if there is a risk that the reader has a problem with getting stale data. If you have a single writer, and you don't care about all data coming through, for instance a boolean that says On or Off, and you care about the latest value, a local variable should be okay.
