This mod swaps pretty much all textures with unlit lower quality ones. Most of the map textures are replaced with flat colored textures, reducing the vram usage greatly.
A big problem with deadlocks optimization is that it uses an absurd amount of vram. Players with lower end gpu's run out of their vram quickly, causing them insane fps loss. Most textures in deadlock are 4k, including pbr textures like roughness, metalness etc. This mod uses a single 1x1 pixel color texture for most of the map materials and instead play around with their color tint option to set their albedo.
Hero materials unfortunately cannot be set as unlit since veils break when lighting is disabled on them (thanks valve). They will still not have lighting fall on them due to a clever trick (courtesy of @Beyonx), however they probably don't give a performance boost apart from the reduced texture quality.
Feel free to give feedback in the comments section of times when you still have fps drops!