Well, based on my family, if a Half-Druzi marries a full Druze, their children are accepted as Druze. So this allows some room for admixture, I guess. But it's rarely done. But we have a Half-white guy (His dad had married an American woman) that did marry a Druze woman. So those kind of windows are open.
There was also a recorded incident "The Rape of Ibn Barbariyah" were a number of Druze women were raped by Bedouins. It's not clear whether there was any pregnancy though. But it was central to the Druze faith to accept those women back and not look at them any differently (although sadly that's always impossible).
Druze should really consider starting getting out of their cocoon