Possible to downgrade graphics?

Heyo,

I'm playing on a potato, and would like to decrease the graphics settings even lower than what the game provides ingame, in order to provide a more smooth frame rate.

I was wondering if anyone knows if there is an ini file or other settings (registry maybe?) that I could tweak?

Currently its borderline playable, but with heavensward I am worried I will be unable to play this game anymore.

Notable settings I want to tweak:

1. Remove texture filtering altogether (currently lowest is bilinear x4)
2. Remove all shadows (currently cannot remove environment shadows)
3. Remove all particle effects (particularly smoke/fire)