Would love to have the function to mirror the web flow preview mode on your connected devices. Similar to how Sketch can do it... This way we can test on the actual devices without having to publish
We've been thinking about this too. Thanks for your feedback!
I'm using Adobe Edge Inspect. Of course not working withing the designer but as soon as something is published to the staging, I check it on iPad/iPhone/Nexus with Inspect.
It's not only a preview, you can also inspect the rendered page on mobile, on your computer, and debug from there... kinda essential.
Edge inspect is including in CC