Big fan of Kenji’s. I have used, with great success, my egg steamer/cookers for years. Wore one out and had to get a new one last year. They make perfect soft to hard boiled eggs every time. The key to getting no graying is to chill them in ice water immediately for hard boiled. That’s always done the trick for me, (even if I boiled them in a pan). I like my cooker, though! Even does a pretty good job of poaching.
What kind/brand of steamer/cooker do you have?