Well, I did resolve it after combining many different suggestions, ultimately it does boil down to just customizing the game with a user.cfg file, all I have in mine is this:
r_antialiasingmode = 3
r_sharpening = 0.8
e_shadowsMaxTexRes=4096
r_antialiasingtaasharpening = 1.0
sys_MaxFPS = 300
r_supersampling = 0
r_ssdo = 0
r_vsync = 1
create a simple .txt file, copy paste that in there, customize it a bit later, but just test if it works, then twink it later, if needed. Rename it to “user.cfg”. Put this file right in the top level directory of the game, with the system.cfg file in there, etc…
Then simply add this line of code to Steam Launcher:
+exec user.cfg
Let me know if this helps!