I still stick to my opinion that smartphones are among the most stolen things and keeping the hardware wallet with the phone, while convenient, it may be pretty risky (to lose the device, not necessarily the funds).
Given as well that many people will be automatically signed in to their email addresses
and use their smartphone as a 2FA, combining your phone with your actual wallet as well really seems like putting all your eggs in one basket. An easily lost or stolen basket, particularly if you are broadcasting to everyone that you own a hardware wallet every time you take your phone out of your pocket.
Another thing that came into my mind was the charging. You seem to keep the port in use. Will the user have to remove the cover every time he has to charge the phone?!
I suppose this would be easily overcome with wireless charging, which most new phones have.