I disagree with adding ANY expo or dual rate in the transmitter for use on Phoenix.

The best bet in Phoenix is to leave your transmitter settings at ZERO (just set up a separate 'sim' model in in your transmitter and use that), as you will need to edit a given model to get it to fly like any real world one you have anyhow, then you can save it as a "copy" and put the edited model in your 'favorites' section once your happy with it. By default my copy of Phoenix V5 has all planes dialed right back re their control responses anyhow, so I've had to adjust every one I want to practice on to get it to feel like my own real ones.
All adding expo to your transmitter will do is to add that setting to every single model in the program, and not all models require the same amount to feel right re the way they respond to your inputs so it will be an utter waste of time, and one that will cause nothing but headaches for you later on (I'm speaking from personal experience of doing just that).