this mod allows you to turn off the lighting in the game (not dynamic lighting) it does not work on all heists and lights on map (Heat Street, Conuterfeit because they use mostly dynamic light) it works when it comes to the inside of buildings and No Mercy Heist, you will probably feel an FPS boost

1.1 Update: Edited file bc first version have dark somke effect just not like good
1.0 Smoke effect showcase:
https://imgur.com/a/FA6Z6kU
1.1 Smoke effect showcase:
https://imgur.com/a/PXIiltX

Note: 1.1 Version it has some lighting because without increasing the identity value from 0 to 0.4 smoke looks dark so there will be some light.

use this to install this mod:
https://modworkshop.net/mod/22724

if it doesn't help you, I recommend that you see this guide:
https://steamcommunity.com/sharedfiles/filedetails/?id=1333839209

the screenshots were taken with the shadows enabled so they may differ!