Oh dear! This old but very helpful post from Davide, that I read only yesterday, completely distroyed my plans. 
I have a gx80 that I have been so far using for out of the water stills, and recently I have been thinking about getting a Nauticam housing with the 6' port for the Pana 7-14 to start using the cam also under water, in order to update my Intova action cam rig.
I thought the port would have supported the 100 meters, hence with a bit of luck it would have resisted even a bit further down.
Now, the fact it is instead given for 75 meters significantly affects this plan.
The idea of spending at least a couple of thousand euros for housing and port and then having to either rely on "luck" during the best dives or leaving the new rig at home for using the old acton cam, are both not very attractive...
I would then ask if anyone has any advice about, and Davide in particular if he has found a different solution for his wide angle shooting (asking him directly an update on the state of his luck in the last 4 years would not be very nice...
)
Thanks!
Paolo