So I went to ds today, did madness normal, and since gms said they fixed BM KC issues in that fight, ill write about my experience:
Pet can KC tentacles just fine, problem is Corruption. He still positions himself wrongly, he takes a lot of time to switch from tentacle to Corruption, and takes an awfull time getting there (forcing me to delay my KC (since he's out of range)). If I have to manually send pet beforehand every time a Corription spawns...
When switching platforms, pet STILL goes out on his way, going up and down on each platform, instead of jumping with me, or despawning/respawning next to me. If you do red->blue, pet will take a LONG time to get near you, delaying (in my case) almost 10 seconds my KC.
Sometimes, on the same platform, after killing Corruption, instead of just turning back and running to the tentacle, my pet would make an detour, went outside of the platform, underwater where the Corruption was, and tried to go through the water to attack the tentacle. Couldn't KC, had to manually call him to me, for him to be on top of the platform, and only then send him to tentacle.
THANK GOD MoP is coming in 2 weeks. Madness is the worst fight ever for a BM hunter atm (pre-patch it wasnt so bad, pet did not have this kind of pathing issues, he despawned and respawned near you whenever you jumped platforms, he would position himself all the time on top of the platform, instead of trying to swim to his target).