Thanks Paul for adding it as a request !
Thanks for bringing this to my attention, Paul.
The reason it is done this way is because of the Cordova CLI. The tool hands off a lot of the Cordova-based work to Cordova CLI. I used to have it baked in myself, but applying Cordova updates was a pain.
For the behavior requested, I think I would need to check to see if/how to hook to Brunch and watch for build changes. What I can do is trigger a rebuild then.
Closing for the moment. Currently only added watch support for web only.