I wonder if such software civilization couldn't automate the exploration process away, so that the beings themselves don't care about it day to day. From the outside perspective, the whole thing will look like a weird blob of something, expanding in the direction of usable resources at speeds close to c. And beings inside may not even be aware they're consuming some "real world" around them.
I guess I've just sketched a sci-fi story. I wonder if someone wrote it already.