Yes “SS strength” should be subsurface strength. Otherwise there is a paramter called “Brigthness”, you could try to turn that down. AFAIK subsurface strength and brightness are all you can change here. Otherwise you could capture a depth map of your tree and also make use of that inside the material Render to Texture Toolset Setup | Unreal Engine Documentation and Render 3D Imposter Sprites | Unreal Engine Documentation