Persona 5 Royal

960x600
Screen Mode Windowed

Scaling Mode - fit
FSR - 5
Half Rate Shading - on

Shadow quality - low
Anti-aliasing - FXAA
Depth of field - low
FPS - 60

Max settings with 100% resolution scale and Medium shadow quality. Very few fps drops (only in big cities and a couple Palace areas, dipped down to 40fps at worst). Averaged 3-4 hours depending on how often I was in a Palace.

Proton Version: Proton Experimental

Graphics Settings:
High Preset but change Framerate Limit to 60fps and Anti-Aliasing to FXAA. Depth of Field and Shadow Quality is optional.

Power Draw/Battery Drain Note: while the vast majority of the gameplay/cutscenes can take around 6-11w depending on Location/Palaces/Mementos. Some parts of the game (including Subway Station and the Main Menu) can drain up to 14.4w of battery. This is most likely due to Generic NPC Crowd counts that appears on screen. 

You can also use this preset on 60fps, but I'll suggest changing Game Resolution to 1280x900, change Rendering Scale to 75% percent, change Shadow Quality to Middle or Low, and change Depth of Field to Low. Be aware that battery draw gets increased 

1440p resolution for clear UI text. Resolution scale in-game at 75% (effectively 1080p). 

Docked Mode

Set the resolution (the cog wheel icon next to the PLAY button) to 4k. Then started the game. Inside game set the resolution to 1280x720p, and fps to 60 FPS. Then I turned on FSR at Level 5, and viola it looks and works great. Otherwise not setting a high resolution on the cogwheel settings (4k) the game would stutter like crazy when FSR was turned on.

Having font issues? Set FSR to on and sharpness to 5, set in game window mode to borderless. Mint experience.