I was watching First Man (2018) and noticed that just before the launch of Armstrong's Gemini mission the capsule's altimeter read zero.
My understanding of the Titan II GLV is that it's 109ft tall so I would expect the altimeter to read this if set to "aerodrome" pressure level (QFE) or something different if set to area pressure (QNH). Unfortunately I don't have a Cape Kennedy METAR from the launch date available to check!
My thinking is this was a mistake in the movie. Surely it must be important for the astronauts to set the pressure in case of an abort? Or maybe not given the distance the rocket can travel whilst it is still possible to abort the pressure setting would be wrong anyway by the time of landing.
It would certainly be strange for a pilot not to set the altimeter before commencing flight.
Another consideration here is the mechanism to deploy the parachutes. Was it based on the barometric pressure or a radio altimeter?