Small correction, 150A through 0.1mOhm is 2.25W because P=R*I^2 but I'm guessing that was a typo.
So what you're saying is, you've been working for at least two months (or ten, somewhere in there) to design a VRM that isn't as good, to push power through traces that aren't as good. When did y'all find out you needed to be able to source 180A at 0.6V? Because that would have been a pretty good time to design the PCB with heavier traces.
Yes, that was a typo. The point is still valid though. The problem is one of how do you test a circuit when you need a device capable of handling massive power at very very low resistance? I don't know of an available resistive load capable of duplicating the ASIC chip in operation. .002 ohm resistors capable of handling 300 amps are not something you can order at the local electronics store. Maybe that is why other companies went the route of dozens to hundreds of chips instead of just two. As to when, it was towards the end of last month when Josh posted we needed heavier traces. He actually has been very transparent about what is going on. The problem is this community doesn't believe anything and is forever looking for the ulterior motive.