Is there a reason for the speculation / discussion about BK "practicing" or studying anatomy with a dummy or animal carcass? IMO, this seems like a big reach and borderline insensitive unless there is something suggesting otherwise at this time.
While BK was probably not a vegan because of concerns over animal rights (it sounds like it was more about compulsion and control, and / or weight loss), if he didn't eat food cooked out of vessels that previously had meat in them, I have a hard time imagining him working with animal bodies / corpses of any kind. Just IMO. He also left Murphy unharmed for some reason and the mutilated dog in Moscow is currently said to be unrelated to the crime per LE.
And while Kaylee's dad mentioned the precise location of Kaylee's stab wounds (in the service of perhaps differentiating them from other victims'), I doubt that he spent much time deliberating on where to make blows. I don't know if we can really speculate on whether or not the manner of death was executed with any manner of precision, or if that's at all relevant at this point. All IMO, but this seems like a strange line of speculation at this point.