Thanks for taking the time to submit this request! As others have pointed out, we are currently unable to add support for splitview within the TrainerRoad App due to the way the app is currently built.
That being said, splitscreen is something that we would like to someday implement, it will just require a major restructuring of our app and a lot of Development Resources. So while this is not on our immediate roadmap, as we complete projects and development resources free up, we hope to dedicate resources to this.
Sorry that I don’t have a more concrete ETA, but I hope that I was able to shed some light on our future goals and direction 
Cheers,
Bryce