Under Settings->Navigation Options->Instruments it is possible to choose “Show Altitude”. Whilst flying it is then possible to switch between the display of Altitude or Height by tapping on the ALT/HGT readout.

I routinely switch to Height when flying, as a direct display of Altitude is available on the aircraft instrument panel, whereas Height is not. A direct height display is useful when flying at low level to help ensure no breach of regulations. Occasionally I forget to change from Altitude to Height at startup, and have consequently flown closer to the ground than I believed I was.

Can this choice of Altitude or Height be made sticky? It would seem pretty straightforward to implement, in a similar way to the “Track Display” option. I.e. “Default ALT/HGT” [Altitude¦Height].