[UE 4.7 R1] "Applying changes to original material and use its use in the world" 35 minutes

All default settings except UI was cheked, lighting mode was ‘unlit’ and it was a translucent material, but it appears to be happening with SpeedTree leaf materials as well (and probably others but I haven’t been able to test yet)

I’m using a static switch and a float as adjustable parameters.