The borg had been reluctant to attempt to dig rubble while exploring the dungeon. He felt he needed over-the-top skills in order to tunnel through. This is now repaired.
Also, he was far to quick to attempt to tunnel through rocks to go somewhere (like a stair). This was fixed, so he will need to have sufficient skills before he attempts to plot a long course through rocks.
The borg is still not clearing rubble, at least not as a low level character. He seems more spastic around rubble now but it doesn’t do him much good.
Right, he will probably avoid rubble until about clevel 10. At which time, he should have sufficient skills to dig.
I should mention with respect to my first comment (yet unpublished) that this was with munchkin_start set to FALSE.