Thanks!
As for the chameleon arch, it seems to be a pretty standard installation inside Tardi! And the Master does (I'm almost certain) state that he ran to the end of the universe, he wasn't put there. And so what if he woke up as Yana on Jack's homeworld? We have no evidence that Jack ever returned there after he left to become a Time Agent, in fact Boe seems to have spent the last few centuries of his life on New Earth.
As for the chameleon arch, it seems to be a pretty standard installation inside Tardi! And the Master does (I'm almost certain) state that he ran to the end of the universe, he wasn't put there. And so what if he woke up as Yana on Jack's homeworld? We have no evidence that Jack ever returned there after he left to become a Time Agent, in fact Boe seems to have spent the last few centuries of his life on New Earth.