If you want a visually way more immersive TT Isle Of Man: Ride on the Edge 3 experience, you must give ReShade a try!
And as I don't enjoy youtube videos which do clickbait instead of simply mentioning their used ReShade Preset settings, I tried my luck. Enjoy!
But see for yourself, ReShade enabled:

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It is free and at least this preset ('TT3-WEEDs_Realism.ini') does not require much additional performance from your system, and it only takes up to 5 minutes to install.
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Before (Vanilla):

After (ReShade):

For more screenshots see section 'Comparison Screenshots' at the end of the guide.

1. Go to https://reshade.me/ and download the latest version.
2. Now execute and install the downloaded 'ReShade_Setup_5.8.0.exe'.
2.1 Follow the screenshots, if you're unsure on how to install ReShade properly.
2.2. Choose Game (TT3)
2.3 Choose DirectX 11 version
2.4 Skip the preset selection
2.5 Select all Effect Packages
2.6 If you did everything correct, press finish.

3. Next, you want to download the preset.

zip-archive: https://workupload.com/file/NgM3EUFGLzG

Simply download my reshade preset TT3-WEEDs_Realism.ini from the link above and extract it to your TT3 game directory:
?:\SteamLibrary\steamapps\common\TT3\

Worries? ...dont worry! Just use https://www.virustotal.com/gui/home/upload to check the files. :)

If ReShade is installed properly, you'll see a short notification at the top of your screen (upper left) every time you launch the game. This will look like this:

The 'HOME' / 'POS1' key is the standard key for enabling/disabling the ReShade menu overlay.
1. When in the main menu of TT3 press 'HOME' and go to the settings tab of ReShade.
2. There set a key to enable/disable ReShade, e.g set it to 'END'. (second line)
3. And also activate (tick) 'Load only enabled effects', for performance reasons.

In the main menu of TT3, or while on your bike, press 'HOME' to open the ReShade overlay and go to the 'Home' tab.
In the first line you can see the name of your active preset.
When you click on it, a drop down shows where you can now select another 'Preset.ini'.
Don't forget to hit 'Select' and the new profile is loaded up.
...for 'TT3-WEEDs_Realism++.ini' - with even DoF enabled - see link at the bottom.

This is how the values of the custom preset look ingame, if loaded properly.

Before (Vanilla):

After (ReShade):

Before (Vanilla):

After (ReShade):

Before (Vanilla):

After (ReShade):

Before (Vanilla):

After (ReShade):

=> For best quality show in fullscreen. Ride or Die...

If you think your rig can handle some heavy load, definitely try this even more beautiful ++ Preset:
https://steamoss.com/sharedfiles/filedetails/?id=2998442751