The Wannsee Conference was January 1942, all the allies were quite fully at war with the axis powers. I'm not aware of any further steps they could have taken aside from total war and industrial incineration of cities (which, as OP's article bemoans, they 110% committed to.)
>Stopping the Holocaust or the Japanese crimes against humanity was, for the most part, a consequence of accomplishing their other strategic goals, not a strategic goal unto itself.
Not true. Ending the Holocaust was a war aim and plans were considered for operations specifically to disrupt it, but nothing was ever proposed that would be as effective as simply winning the war.