I have noticed that parameters inside materials (not only material instances) can be changed without recompiling the material, I don’t even remember if it’s that way with normal UE4 as I haven’t used it for a while.
Really it’s not much trouble to create a material without VXGI switched on, when it’s roughly how you want create a material instance and switch on VXGI and boom, hardly any waiting.
@.
I’ve had some light leaking/issues when using Ray Traced Distance Field Shadows alongside VXGI (with Directional and Spot lights).
I’m still playing with it to see what’s really going on/if it’s my fault.
EDIT: I have to use VERY bright spot lights to really see behavior.