I recently got a Razer Kishi after breaking a few of the orzly Stadia controller screen mounts and it felt like a dirty after thought as it totally strips away the console feeling of using stadia. I can use the controller or Kishi up until i get to in app Stadia's interface. Then you awkwardly have to start using the touch screen on your phone for scrolling and booting up the game, this two applies to messaging, you cant use the controller and have to either dismount the phone from the stadia controller mount or razer kishi etc type your message and then re mount the phone before continuing your gaming.
Hi @Greaze,
You're absolutely correct. The Stadia phone app seems like it was (strangely) designed to only support touchscreen input/navigation outside of a gaming session.
If you haven't already, please be sure to use the feedback option in the Stadia app to share your thoughts on this with the development team.