I have tried 2 ways of checking: 1) default start-up and 2) start-up with config.
Consequences of both are same.
In first one I as common person went to setting then graphics section and turned on FSR with sharpness 100%. Everything seems good but no, after restarting DbD entire effect of this manipulations are lost. I need to go to graphics setting again and simply turn off and than then turn on FSR withoun changing allready maxed sharpness to back the effect.
In second one I used config. I simply experimented with variables in that file and used "read only" property but no good result.
FSR resets always, please do something with it.