Quixel Megascans vertex paint blending material - need to add bump offset, how?!

While made simpler vertex color blending materials in the past, I really like vertex color blending material Quixel provides for their Megascans. So I don’t really want to re-invent the wheel just because I need a bit of extra functionality.

Has anyone tried adding Bump Offset to that material? How would I go about it?