Thanks but my other question still goes un-answered.I've edited the gamemode to use custom bricks for my maps, so.. I'm wondering if this works.
If you edit the gamemode.txt to use JVS Content I don't see any reason why it wouldn't work.
Keep in mind the new creeper can't go through bricks regardless of brick settings due to an update in v21 which meant that bricks placed within bricks didn't get a collision shape.