I've used several systems and still do. Principly QFE below transition altitude except for 70s flights to Moscow where we used similar tables to the current Chinese ones. Fortunately it was three pilots and we wrote everything down which lessoned the workload but there were times no one except George was flying the aircraft.
Bergerie mentioned what we used on the VC10 which lead to the game park warning system incident into Nairobi were confusion reigned and they did a touch and go at night in a clearing.
My third outfit was QNH but our training was high level and flying was very sporty which led to an incident in my line training flying into Geneva 05 with some very inclement weather.I elected to do a dirty dive in the hold without doing the full approach procedure which went very well until the outer marker check which showed a 1,000ft plus discrepancy. The training FO and captain were as puzzled as moi meme until I realised the discrepancy was the beacon altitude above the threshold. I was following the 6 degree glideslope which was easily rectified; throttles idle; land flap and flight director off.
Later I got into gliding followed by instructing which is another ball game.
UK QFE in the circuit but teaching height assessment using visual clues..QNH cross country with the difference with standard written down for airspace.
France has a simpler system for the mountains but that is with speed in kph, altitude in metres, vario MPS and using hiking maps marked with circles of 10km increments with the QNH/standard difference scrawled down. The above allows one simply to calculate gliding range to land able terrain (at 20 to 1) and how far up a mountain face one is going to arrive (hopefully). It becomes more complicated if your glider instruments are impérial and your position reports have to be in altitudes (french) not forgetting the earlier flight computers could be in another set of numbers.
I did have an air miss during circuits whilst instructing at Blackbushe where an incoming aircraft forgot to set QFE and came through the circuit just below cloud base on his way to a dead side joining.
Have a sophisticated instrument for paragliding..set to take off QFE for return to top land and my car but on cross country it’s back to mental gymnastics wrt airspace. Fortunately there are GPS systems programmable with airspace.