How can I apply zoom mode on iPhone 6+ but not iPhone 6

I would like the app to use the adjusted layout for the iPhone 6 using auto layout, etc., but then on the iPhone 6+ use the scaled version of the app from the iPhone 6. I tried to set just the iPhone 6 launcher image in the LaunchImage asset directory. but it still works on iPhone 6+ using its own layout and not zoomed out.

The reason I am trying to do this is because the app has a lot of free space due to the large screen size and looks better with the iPhone6 ​​layout. The tricky way to do this is to work with the UI to use extra pixels, but I thought that as an initial step, the enhanced version on iPhone 6+ would be better than what we can get with auto-open and co-author. But it might not be a good idea.