I think the reason you see no 'Save' option there is because the 'Data' dropdown isn't set. If you set it to some value, 'Save' should appear. That said, I'm seeing an issue on my Android device where the widget is losing a previously set 'Data' option, so I think I do have a bug to log here. I don't think it is related to the Custom Breaks.
In somewhat related news, we're getting around to the work we've been planning for some time to improve mobile/dashboard sync -- as you may have seen its a bit unreliable right now with regard to changes being made on Android reflecting on Web and vice versa. Do you have any interest in being a Beta tester for a pre-release mobile sync improvment when it is ready on a development server. If so, let me know. If anyone else is reading this, please PM me if you'd like to be part of that test.