First you need to unlock the FPS with this Mod:
https://codeberg.org/Lyall/MGSDeltaFix/releases

Then you need to download following files:


The files bnvngx_dlss.dll & sl.dlss_d.dll are included in this Streamline SDK 2.9.0:
https://github.com/NVIDIA-RTX/Streamline/releases/tag/v2.9.0

The files are located in streamline-sdk-v2.9.0\bin\x64\

The newest DLSS file can be downloaded here (replace if already there):
https://www.techpowerup.com/download/nvidia-dlss-dll/

you need to place the 3 files into:
MGSDelta\Engine\Plugins\Marketplace\nvidia\Streamline\Binaries\ThirdParty\Win64

Also force the newest DLSS Versions with DLSS Override in the NVIDIA App!

Lastly, you need to add the following section to the bottom of Engine.ini (located here): C:\Users\*YOUR_USERNAME*\AppData\Local\MGSDelta\Saved\Config\Windows

[SystemSettings]
r.NGX.DLSS.denoisermode=1
r.Streamline.DLSSG.Enable=1
t.Streamline.Reflex.Enable=1
t.Streamline.Reflex.Mode=1
r.Streamline.DilateMotionVectors=0
r.NGX.DLSS.AutoExposure=1

Have fun!

demo:
https://youtu.be/EA61a3EJK7o