Hello, for some reason they made the game run in a very small screen, with huge and distracting borders and unnecessary UI all over the screen (imo). Just simply use the zoom option;

1. Go to the game. Press Steam + L1, adjust the screen until the characters avatars from the left and the item box from the right disappears. Make the character read something too so you can adjust the text box from the game even more.

2. Now add the "Toggle Magnifier" for one of the buttons in Controller Settings. For those who don´t know, during the game press the Steam button->Controller Settings->Edit Layout-> buttons (R4 in my case)-> System-> Toggle Magnifier

There, now you can actually enjoy the main game on your Deck screen without looking so small and distracting, just press 1 click to zoom out whenever a CG pic appears to get the full picture or when you want to see the full portrait of the characters that appear from time to time (the rest of the dialogues just use the characters small avatar so you should be fine here)