There is nothing you could tweak about that. The glitches are caused by a deferred rendering technique the game uses, which subdivides the image into many small rectangles for applying various effects (e.g. lighting). Unfortunately this technique can’t be perfectly stereoized.
Please leave the 3D-Strength at default. I tested the game for quite a while and considered the glitches acceptable at the default 3D-Strength (1.0), otherwise I would have chosen Z3D as default for the game. The glitches get worse when you raise the 3D-Strength.
The other option you have is switching to Z3D.