The version on DevZone is not that different from the version currently used in UE4, most of the changes are related to OpenGL and others are small performance improvements. And there are some functional changes made after 20094040, specifically I added a tracing refinement pass that allows you to use e.g. 4x sparse diffuse tracing on scenes with very fine geometry and still get a complete result, without holes. I’ll probably update the version in UE4 week, to include those new changes as well.