Prototype settings per flow

I have been trying to prototype desktop and mobile designs, however, I am finding that I need to have my desktop and mobile designs on separate pages in order to assign each design its own device. It would be nice to be able to assign a device per flow. That way I can not only view the designs side by side instead of switching pages.

This feature request was posted earlier on the forum. You can join others and vote for this idea here: Multiple Flows Should Have Different Device Frames.