GH3 owners: is video "ISO Overdrive" possible?

About a year ago I established that both the GH1&2 could easily reach a two-stop increase in stated video ISO limits with camera settings manipulated: 1600 to 6400 in GH1; 3600 to 12,800 in GH2.

Would an intrepid GH3 owner please give it a try as follows, which works for the previous GH's?

• Set up your camera in video mode, S or A priority (not M), with ISO set to highest video manual setting (6400 in GH3, I think). Now, go to a dark setting, or set a very high shutter speed to give you a clearly underexposed image by histogram.
• Then simply set ISO to "Auto" and, if it works as previous GH's do, you will see the image brighten, which I showed to be 1EV previously.
• Now, on top of this 1EV ISO boost, switch to ExpComp and start clicking upwards. Nothing happens with the first six clicks to +2EV. Then, lo and behold!, the next three to +3EV bring progressive brightening of another 1EV - for ISO 25,600 in the GH3, if it works; or 6400 in GH1, and 12,800 in GH2.
• The 2EV gain is only possible with m4/3 and 4/3 lenses, where ExpComp is active in S, A, or P mode. With legacy lenses, 1EV gain with Auto ISO, as EC not active. And as full manual mode locks out both Auto ISO and EC, no gain is possible with any lens.

I found in the GH2 that 12,800 was only marginally usable, and that only in B/W mode. The GH3 should be much better if it works.

Thanks in advance for giving your GH3 this video "ISO Overdrive" a try, you lucky folks - whom I hope to join soon!

Pete