Already asked on the modding subreddit, but neither I nor the (very kind!) subreddit users could come up with a solution so I figured this was the best place to ask for help, because I'm tearing out my hair here.
The main problem is ENB. I removed my preset and with only ENBoost I had the most annoying screen tearing (?) and stuttering issues. Installing an SSD helped a bit. As soon as the d3d9.dll is gone the problem is almost gone. Even with Vanilla (all DLC and cleaned) + STEP Textures + USLEEP + UHRP + SkyUI + SKSE + OneTweak + Crash Fixes I have screen tearing when turning around and occasional stutters. Framerate is stable, but it does not feel smooth at all.
i5 4570 4x3,2GHZ
EVGA GTX 1070 FE 8192MB
Using Mod Organizer.
Skyrim.ini and SkyrimPrefs.ini generated with spINI.
As I said, main issue is ENB, but I rolled back to vanilla today and with my minimal base mod list and no ENBoost some stuttering still occurs. I've tried every fix I could find on the internet and nothing helped. Any advice or help would be very much appreciated!