@joshbooker I am afraid this won’t be possible as we don’t know what controls a form contains beforehand. We can expose a Change event which will tell what field changed. One can act as needed from there using the Condition property. At some point the UI should be a lot better for cases like this.
You are absolutely right that cascading combos are a common scenario. We will think of a way to make it easier to define the relationships between them.