Actually, thanks goes to a buddy of mine, "Neovita", he first made me aware quite some time ago of this problem that nvidia has and at first they offered the "Fog Table Emulation" setting in their driver, later they removed that option from the control panel and it was a hidden setting possible to activate via RivaTuner up until 9xxx cards.
With later cards the setting was simply removed completely from the driver, since then we are as said in the start topic, depending on application/game developers to let us deactivate such fog features.
After a lot of google and getting more desperate with my 780 Ti I was idling and braindead in TS, then he made a comment "Maybe you'd find the fog texture"... First thought "Games use post-processing to render fog from a variable since long, probably no success... - *Open graphics01.zip and yells* YAY, FOUND IT!" - That's the story...
TL;DR:
Enjoy the find, thank "Neovita"
P.S.
Well, I'm not aware of the actual situation regarding the EULA and the not-anymore-existing Ascaron Entertainment so I decided to post instructions only without a modified graphics01.zip since it's modifying original files.