Well, I received it today as promised from All e RC. I did indeed get the new P2 with the hole in it, and the new H3-3D. I'm actually keeping the new unit as a spare, or selling it I'm not quite sure, so I decided to dremel a hole in one of my existing P2s. This worked fine, and I was able to mount the gimbal no problem.
Of note, I did not upgrade the firmware on the P2 to version 3.0. What I found out is that everything works fine, except the range of tilt out-of-the-box on the H3-3D is very limited. Maybe to 30 degrees, and you can't look straight forward or completely down. The only way to adjust the tilt, is to install the 3.0 firmware. And of course with that firmware, of course you run into all kinds of flight limitations if you live near big airport in the city.
More to come after I look at the footage, but the FPV feed was extremely stable.
EDIT: All the gopro footage on the computer is showing jello. I used the grey rubber balls, maybe I will have to try something lighter. ****, not good.
EDIT 2: I noticed the no-drop washers weren't pushed all the way in. That helped immensely, but there was still some wobble here and there with rapid speed. I also noticed that cutting a hole with a dremel isn't quite enough clearance. The y motor spins, but can still catch the bottom of the battery. When it starts to catch you get a lot of jello, then it goes to protection mode, then wakes back up. So I will need those washers to standoff the zenmuse a touch as the current P2 is just barely (like a mm) too close to the battery if you drill hole.
Finally, the plastic washers are a one time thing. They give you a spare set (only two are mounted per the manual) but I have found no way to change out the rubber balls except to just cut off or break the washers. And as I found, they are necessary. They don't just act as an anti-drop, they help isolate the gimbal.
EDIT 3: adding some washers and going back to all the white balls seems to have solved the problem. Got to make sure the pins are snug. I hope I can find more of the pins from DJI, because if I ever want to move it now I am stuck. The anti-drop pins are actually critical for stability of the image.