The zddp is old wisdom that doesn't apply anymore. What you're after is anti wear film strength and there are plenty of modern oils that get that property without the pounds of zinc they used to need to get it.
https://540ratblog.wordpress.com/2013/06/20/motor-oil-wear-test-ranking/
https://540ratblog.wordpress.com/2013/06/20/motor-oil-wear-test-ranking/