When I think about this I like to check what Jake came up with here https://speakerdeck.com/jakewharton/the-state-of-managing-state-with-rxjava-devoxx-us-2017?slide=220

Your code is fine and can be tested inside the JVM. On the other hand, I could see it being an overkill for what it does. It does not have any side effect, it does not set anything, nor get anything, that is why I would not include this intent into the flow.

What happens when you come back to this activity once it binds to the state binder? Don’t you have the mainModel.startBrowserActivity kicking back again?