First of all we must open the file explorer and go to the following location.
\Steam\steamapps\common\Fallout 4

Once in the folder, you must locate the file called Fallout4_Default.ini


They open it with a notepad or any code reader and look for the line of code iPresentInterval This will come with the value 1, they must change it to the value 0 and save the file. And it should look like this iPresentInterval=0

We open the file explorer again and go to the following location.
Documents\My Games\Fallout4


Once in the folder, you must locate the files called Fallout4.ini and Fallout4Prefs.ini. We open each one and look again for the line iPresentInterval= which is surely in value 1. As in the previous step, we must change it to the value 0. Again it should have been something like this iPresentInterval=0

Apparently the new update, in addition to breaking some modifications, also altered this method of unlocking the FPS.
The best solution I found was to disable window mode or borderless display and leave it full screen. In this way the FPS are delimited. I did this with iPresentInterval=0

When you enter full screen mode and open the game, the iPresentInterval values ​​may return to their original state, so you must reopen the game files and set the values ​​to iPresentInterval=0

By: @Kilroy

Here are some things the community likes.
- Right-click and go to properties on your fallout4.exe and fallout4launcher.exe, and make sure high DPI scaling is checked under compatibility -- change high DPI settings.
- Reinstall the game
- Set windows scaling to 100%
- Delete "Fallout4Prefs.ini"
- Run the game again that will redo the setup and you can now select normal UW resolutions like 3440x1440.

You should know that by unlimiting the fps, the game does not have a VSync option or fps limitation, its components will work at their maximum to have the highest amount of fps possible. To avoid this you can limit from the control panel of your graphics card. Another option is also to use "MSI Afterburner" with its extension RivaTuner to limit the fps within the game in addition to other options that include these applications.

Physics is still tied to frame rate. So when you unlock the fps, things like voices, some objects, doors and so on will not work correctly. This can be fixed with a Nexus physics mod.

https://steamproxy.net/sharedfiles/filedetails/?id=3221936864&preview=true