This, in my case fix stuttering in the game on deck, although you have to do this every time if you wanna play persona 5 on the deck, although I am looking for a permanent fix so you don't have to do it each time.

Anyways I hope this was helpful, if there are any questions or advice leave them in the comments, I would be happy to discuss with fellow deck users and persona fans!

1. Press Y
2. Navigate To System

3. Navigate to Config

4. Navigate To Display Settings

5. Change the resolution to from 800p to 720p, and the display settings from full screen/borderless to windowed

6. Hit A twice to apply

!!!!!! YOU HAVE TO DO THIS AT EVERY RESTART OF THE GAME

Persona 3 Reload:
https://gtm.steamproxy.vip/sharedfiles/filedetails/?id=3405995976