My wife is not from the US, and she’d never had the Dor Yesharim blood test taken. We liked each other and thought it was headed towards marriage, but didn’t know if we should wait for her to get tested.
Her father (in Israel) went and asked R’ Chaim Kanievsky if we should wait. He replied “I didn’t have a Dor Yesharim test either”. My father in law said, “True, but now that there is an option, should they wait?”
R’ Chaim said “No, and I give a brocha that all their children should be healthy.”