"I'm heartened to hear what you have is 2k lines, it will make a re-write much less painful if it's needed :)" My takeaway was that they successfully identifie

"I'm heartened to hear what you have is 2k lines, it will make a re-write much less painful if it's needed :)" My takeaway was that they successfully identified the small essence of the problem ("It's DAG, stupid!") and wrote a relatively few but intelligent lines of code to solve it. And they have gotten pretty far with the implementation. God does not require rewrites of such.