Yes, it is all explained in the thesis, and the basic ideas are simple. The implementation not, they had a 14k lines of code C implementation they said, never released to the public, and full of bugs I guess due to C. Around 2010 someone of the gEDA project, I think it was Mr Anthony Blake, tried a C implementation, which was working partly, but no one was able to understand the few thousand lines of C code, and he gave up.
One point which is not that simple is rip up and retry. Tal Dayan was talking about that in his thesis, but I had no idea how it should work. Undoing region split seems to be impossible. But now I think that he did not really mean a ripup, but only saving some states. That should be easy, we may save the state maybe whenever 10 more traces are routed, and then when we notice during the routing process that some traces can not be routed as they are blocked, we can jump back to a saved state and reorder the remaining traces hoping that them they will not block each other.
