I often find Nazi wins timeline boring, they're alway the same. I have only found a few I like (like Murder in the Hitlerstadt). Sadly I think the problem is that people focus on a theatric evil and absolutism, which the Nazi did in fact lack. The evil of the Nazi while grand in scale, was extremely petty and mundane when we goes down to the smaller scale. The Holocaust was industrialized because the German bureaucrats found that while their soldiers was willing to commit the atrocities, it traumatized them and hurt the army's morale. The people who planned it, took a legalistic perspective and did their best to ensure the eradication of the Jews was legal. The Nazi also lacked the absolutism if the Kate Communist party, there was many actors who sabotaged the Regime's plans, ano the Regime had to regularly back down.
What really made Nazi Germany so incredible weird was the fact that, it was bunch of weird undisciplined amateurs, who lay the course, while a rational bureaucracy below them tried their best to make their plans into reality. In normal states there's someone in the top who limit the madness, and if not the bureaucracy us usual to incompetent to implement the craziness. But in Nazi Germany the crazy was implemented by rational bureaucrats.
The big problem with the Slavic Genocide is that it will happen in "peacetime" and the enormous scale. Simply put the German population will be unwilling to see several generation of young men return completely traumatized in peacetime, which will be the result if Germany have to murder 100 million Slavs, and death camps can't run fast enough to murder so many people. It's not because of the morale objections to genocide which will stop it, it's because the German population will be unwilling to pay the human cost (for Germans) of it.