I'm waiting for the directors cut on Bluray or VOD when it's released.

Not until June 2019 for the director's cut unfortunately..

Came across this article, which should shed some light:

https://www.vox.com/culture/2018/11/28/18113504/house-jack-built-lars-von-trier-unrated-r-rated-theater-streaming

Watched it yesterday. I agree it is a really good movie, possibly could become my favourite of all Von Trier films although I will definitely not watch it again until the unrated version is released. I believe it is definitely supposed to be more brutal/nasty in what you see onscreen (the breast being sliced off and more lingering shots of the dead bodies of the two boys) - I mean if Antichrist shows in graphic detail what it showed, there is no reason why THTJB doesn't need to..

Kudos to Matt Dillon, he has never been better. He was genuinely a believeable serial killer.. perhaps the most memorable since Buffalo Bill or Hannibal Lector. The final act does go more arthouse, but this is Von Trier so.. hardly surprising. Oh and it will be divisive, like most horror released this year seems to be.

Ah then you do have the unrated version/director's cut. In the cut I saw, you don't see him even start to cut the breast. It is all implied after it cuts to him throwing one of them onto the cop car's windscreen.

Mark Kermode during his review of the movie said Cannes is where film critics' heads turn to mush .

Right. It was the kids, the misogyny and.. the duckling..