Cornish Jack
Basically NO.
I've been flying in mountains for 25 years after doing a unique weeks course with Jaques Noel who was the top professional mountain flying instructor. Part of every day was pointing out crash sites and how they got it wrong.
I am still learning about weather, orographic cloud, rotor and valley winds in spite of learning how to forecast 50 years ago and similar period observing from land, sea and air.
Altimeters are set to QNH for airspace and transiting goals between mountains. Displacement is purely on eyeball. Got caught out once as thought I was further away judging by the height of the fir trees until I could see the blades of grass having assumed that the trees were 60ft..in the upper slopes they are much shorter. The biggest danger in the french alps are wires followed by collision and lastly flying over colls where the air mass might be totally different and form a wall of cloud.
High G is used in gliders to avoid exceeding vne and flutter..used it once when low level aerobatics went wrong.
They are built far stronger than conventional aircraft..my first was tested to 12G.