Reducing Jewish deaths would require Hitler to radically change his oratorical style. Just like modern stand-up comedians, Hitler began many of his speaches with a series of jabs at minorities: Catholics, gypsies, communists, homosexuals, Jews, etc. Whichever minority earned the most boos from the audience became the topic for the rest of Hitler's speach. By focussing his audience on a minority group, Hitler was able to up lift his audience by blaming all their problems on some one else. It is much easier to blame your problems on outsiders than to change your own ways.
That is a classic schoolyard bully tactic.
Secondly, Hitler inspired his German audiences with promises of "lebensraum." He promised Germans that they would own plantations in Eastern Europe recently vacated by Jewish, Slavic, etc. untermensch. Remaining untermensch would be slowly worked to death for German profit.
What Hitler failed to understand is that bullying produces rapid short-term results but poor long-term results. Bullying victims/slaves only work hard enough to avoid beatings. Ergo slaves rarely work hard enough to turn a profit in an industrialized economy. Hitler enslaved hundreds of thousands of Jews and slowly worked them to death, but slaves are ill-suited to manufacturing sophisticated modern weapons and quality suffered.
OTL Canadian artillery officer George Blackburn reported that significant numbers of German artillery shells fired against him were duds. Many of those duds were manufactured in Czechoslovakia.
If you want Hitler to exterminate fewer Jews, you need to convince him to be less of a bully.