Set the preset to Medium, but set the Rendering Scale to 100%.

While the majority of the gameplay will remain at 60fps (with a exception of visually intensive zones and Multiplayer); Effect Modes menu, Multiplayer Menu, Video Tutorials and Zone Transition will/may cause performance drops. I suggest adjusting the TDP Limit, GPU Clock Frequency and In-game Rendering Scale based on the provided config.

OlliOlli World does not provide any sort of Graphical Settings, but I suggest disabling V-Sync in-game. 

As this is a fast-paced skateboard arcady game where Response Time and Minimum Lag Time is important: please keep the Watts at 5 or more. go below that number and you may experience Input Delay

While this config is based on my own custom Engine.ini file: I recommend heading over to the game's Engine.ini and just place TAAU (r.TemporalAA.Upsampling) and Resolution Scale (r.ScreenPercentage) under [SystemSettings] for the most optimal experience. 

[SystemSettings]
r.TemporalAA.Upsampling=1
r.TemporalAA.Algorithm=0
r.ScreenPercentage=70

Optional: since it's a DirectX 11 title, you can add additional lines to reduce Shader compilation stutters, but I'm still experimenting with it.

In-Game:

While most of the config test was based on the in-game benchmark, please note that Power Draw and Average Framerate will be depended on what level you're currently on.

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 

The graphics preset should be around Low (or custom if you want Volumentic Fog, Motion Blur, Depth of Field and/or Real-Time Reflections). You might need FSR2.1's Quality or alternatives.

Due to some minigames (primarily SEGA Arcade games) being tied to game speed, it's highly recommended to set the in-game framerate to 30fps, as it'll switch to 60fps. You can still use SteamOS's Framerate Cap to 30fps or 40fps for the vast majority of cases (no pun intended) but I suggest setting in-game framerate to unlimited for it.

The graphics preset should be around Low (or custom if you want Volumentic Fog, Motion Blur, Depth of Field and/or Real-Time Reflections). You might need FSR2.1's Quality or alternatives.

Due to some minigames (primarily SEGA Arcade games and Master System) being tied to game speed, it's highly recommended to set the in-game framerate to 30fps, as it'll switch to 60fps. You can still use SteamOS's Framerate Cap to 30fps or 40fps for the vast majority of cases (no pun intended) but I suggest setting in-game framerate to unlimited for it.

Do note that some of the areas within the Ijincho map will drain far more battery life than the entire of Kamurocho map. Be aware if you spot sudden battery drains.