It's a problem. I don't know the solution to yours, but I have a similar problem. I have a Phantom 4 Pro plus with a built-in screen. No cell phone needed. I didn't know I needed a cell phone to fly a drone, until the RID thing came along. You and I & others are supposed to monitor our cell phone while flying (keep with sight at all times!) the drone while the cell phone does nothing but supposedly monitor the RID. 

How can the drone be flown with an ipad and monitor an app at the same time? Some type of split screen arrangement?

I suspect I know how this is going to be handled by 99% of users.