The sudden shift to the original program at the end of the "pretend like you're reasonable" tree feels a little abrupt and flavorless. Perhaps it could branch into two paths, and play up the roles of the inner-regime figures in the decision making more?

What I'd picture for this is something like as follows, with the branch starting when the Communist threat is dealt with and the question remains as to the status of Germany re: the Western Allies in the new world order. This would have two branches -

One where you get into a civil war between the 'strange bedfellows' of those conservatives who never quite bought wholeheartedly into Nazism and those in the new establishment who favor the 'new path' of accomodation with the West, versus the older-school Nazis who want to enact the original program in full now that they are in a position of advantage / have put it off so long. The unexpected (possibly violent) death of the Fuhrer would seem like a good catalyst for that kind of struggle. Himmler would be a natural leader for the latter faction, while you could probably have something like a Schact - Helmut Graf von Moltke - [Pick an old Junker general] troika for the former.

The other path would, naturally, be an expansion of the current ending, where the West finds up that making friends with those who hate you on the grounds that you both hate communists only works when it suits the Nazis, not forever - the mask comes off, the knives come out, and the play for world domination is made. The use of an assassination or other death to start the other branch would play well here, I think, by making clear that the rather more politically astute Hitler of the faux-liberalist branch is still just as malicious and hateful as in the primary path - he just decided a long game suited him better, and to focus on playing the west's weaknesses against them; if fate or foul play doesn't prevent him, he'll play that to its logical conclusion.