I put a Ph2V together for a friend and flew it to get everything tuned for him...and returned it. So it is not in front of me to confirm my recollections....but....I don't remember any gimbal tilt control ON the transmitter. It has, as you note, a 1 dimension stabilized gimbal, tilt stabilized but not roll stabilized.
The manual tilt control you wish to establish is gained and controlled through a wifi connection with a iOS device such as an iPhone, iPad, iTouch (or Droid device...I think). There is an app....go to Ph website OR iTunes. There is a funny bracket to mount on the Tx which holds your smart-device as a screen for FPV transmission of what the Vision camera is seeing and recording......once you get the wifi connection between the two established.
That smart-device connection gives you live-view, almost unlimited control of the camera, on-off, still, video, resolution, etc., BATTERY CAPACITY, AND tilt control of that one dimension gimbal. The Ph2V almost isn't worth it without the iOS device.
One note. In my limited flights I was using an iTouch. The FPV started out real time but after some minutes and some recording I began to realize the screen view began to lag behind real flight view....up to 4-5 seconds. Since it was not my bird and not really my problem to solve I never got further than an internet search and there was info that others had experienced the same thing...seeming to relate to the version of iPhone used. I am sure there is a ton of information about that by now if you look in the right place.