Ryzen 5, Win 10, mods - Stable but constant stutter in combat, need help!

[Ev3rgr33n]

Hello guys, I'm one of those "nothing works, I've tried everything"...
I'm going to detail my problem, then my specs, my load order and finally everything that I've tried. I'm pretty experienced with FO3/FN:V modding (on Win XP/7 at least), but I can't figure out what's going on here. I'll try to be as clear and precise as I can.

The issue: after many headaches, I managed to get the game running with no crash, no stutters, with mods (all details are below). The only issue is that whenever one or more NPC enters a combat state (melee or ranged, so it's not related to particles, decals and the like), the game starts to stutter. It freezes for like half a second every second or so. If I kill the NPC(s) or holster my weapon and the NPC stops being hostile, then everything goes back to normal. The framerate drops to around 50fps when killing the caravan and its guards in front of Megaton (~6 NPCs), with the Protectron shooting laser and the mr Handy (Deputy Steel) using a flamethrower. I have a save at that exact spot so I can test and replicate the problem. I'm using the Steam GOTY version btw.

Specs: (brand new rig)
- Win 10 Home edition (I did the FCU update)

- ASUS Crosshair Hero VI X370
- Ryzen 5 1600x (6 cores/12 threads) OC @ 4.1 Ghz Stable w/BeQuiet! Dark Rock 3 cooler ( 60c max temp after 24h of AIDA64)
- KFA2 GTX 1060 6GB EXOC
- 2x8GB G.Skill FlareX 3200Mhz CL14
- Toshiba A100 128GB SSD (boot drive)

- 2x 2Tb Seagate Barracuda HDD's (Programs, Data, Games)
- Samsung 840 Evo 512Gb SSD (Programs, Games, Steam main directory)
- Corsair RM650x PSU, 80+ gold, 650w
- CoolerMaster MasterCase Pro 5 w/a s*** ton of fans.

Load Order: (planned to add more, this is just "the basics" for me)

Fallout3.esm

Anchorage.esm

ThePitt.esm

BrokenSteel.esm

PointLookout.esm

Zeta.esm

Unofficial Fallout 3 Patch.esm

CALIBR.esm

CRAFT.esm

FO3 Wanderers Edition - Main File.esm

DCInteriors_ComboEdition.esm

Project Beauty.esm

DarNifiedUIF3.esp

megalight.esp

VTHideout.esp

MoreMapMarkers.esp

Dree Perks.esp

FO3 Wanderers Edition - Main File.esp

FO3 Wanderers Edition - DLC Anchorage.esp

FO3 Wanderers Edition - DLC The Pitt.esp

FO3 Wanderers Edition - DLC Broken Steel.esp

FO3 Wanderers Edition - DLC Point Lookout.esp

FO3 Wanderers Edition - DLC Mothership Zeta.esp

UUF3P - FWE Patch.esp

Realistic Interior Lighting.esp

midlifecrisis.esp

midlifeAnchorage.esp

FO3 Wanderers Edition - More Gore.esp

JIP Fast-Travel Anywhere.esp

CASM.esp

Merged.esp

FOSE plugins: Stutter Remover, NVAC, OneTweak, UiO, Enhanced 1st person camera.

Other mods: DarnUI with Revelation UI, NMC texture pack Max quality. Replaced a few NMC's texs with Ojo Bueno (NV Version) ones, and some custom made ones (2k diffuse, 2k normal max). Replaced Project Beauty heads texs with Fallout Character Overhaul (NV version) ones (Works pretty fine btw).
I should point out that every time I dl a mod, I unpack it and check every single textures to removes alpha channels that are useless, properly compress and mip-map them using PS and Nvdia plugins. Most modders don't think about this and leave blank alpha's on the diffuses, glow or metalness. Removing them uses less memory at runtime.

What I've tried so far:

We all know that Gamebryo and multithreading aren't good friends. I use Process Lasso which allows me to set CPU affinity/priority for FO3. Since I'm on a R5 1600x, I set Affinity to CPU 0 and CPU 2, which are my physical cores (meaning, not my logical ones, not my "threads"). Priority on High. Tried without Process Lasso and the game tends to CTD when I get fried by flamethrowers and shot at from that Megaton caravan I was talking about.
In both Fallout.ini and FalloutPrefs, I set iNumHWThreads=2, bUseThreadedAI=1 and all other "threaded" lines like Blood, Morpher, Temp and Particles to =1 EXCEPT for Audio of course. Tried with and without those, various combinations, still the same.
My fose_loader.exe, fallout3.exe and FalloutLauncher.exe have the LAA flag (did it with CFF Explorer), and are set to Run as Admin and XP SP3 compatibility.
The game was initially on my 840 Evo SSD, but I moved it to one of my HDD (which is brand new) and it's the same story.
Tried messing with Fallout Stutter Remover settings (tried ALL of em), and the ReplaceHeap setting made the game much more stable, even though it's usually not recommended. I also tried without FSR, same issue. Tried to uninstall all of my mods and toggle off ArchiveInvalidationInvalidated, same again and again (I'm using FOMM btw). Clean install didn't change anything. Installed DX9, .NET Framework many times. Tried using enbboost & latest FONV/FO3 enb - the funny thing is that ReShade doesn't work, enb does work however and I can get the in-game GUI BUT the effects do nothing, only the injector version works and it systematically leads to CTDs. So no hooks .dll seems to work here. I also tried to disable SMT (Or Hyperthreading, same thing) to no avail. The combat is simply unplayable while the rest is perfect.

I'm at a dead end. I suspect Win 10 Fall Creator Update to be responsible for most of this, but as is, the game is unplayable. I was planning on doing all Fallout games from 1 to 4 but I'm afraid that it'll be the same kind of problems with FN:V, which is my favorite. However, from experience I found FN:V to be much more robust and more optimized. I heard about Tales of Two Wastelands recently, could that be a way to play FO3 decently? Do anyone else has the same kind of issues and hardware than me?

Thanks in advance :)