This is EXACTLY what I was looking for! Unfortunately, though, I'm getting an error:
Any idea what I'm doing wrong? I'm using the script call like this on all nine tiles:
pbPushBigBoulder(3,3,[4,6,7,8,9,10,11,12,13])
Edit 5/25: As an FYI, I just updated to v20 and same error is still there.