Which games or computers actually get to play each other is ultimately dependent on what kind of equipment our testers have or are able to borrow. Rule of thumb number three is that matches between opponents whose ratings differ by more than 400 points are meaningless. The outcome of such a match does not provide statistically meaningful information. No, but we don't accept early, grandmaster-style draws. Normally, a game is allowed to go on a bit further than human players would have done.
Many testers also follow their own rules.
Gunnar Blomstrand, one of the more productive, generally plays on until one of the computers evaluates its position as -10 or below. Super Expert, Hiarcs and some other computers are able to resign on their own, and of course we accept that if it happens. We don't like them, but there is not much we can do. If we disqualified results from games played with such a library, then surely someone would protest against that. Yes, a game is allowed to continue even if the tester can see that it is going to be a duplicate.