@korina@rittels, thanks for the explanation. The “issue” was with the newly available modelElevation. My plugin expected that there will be also temp-surface if there's modelElevation. It's great that modelElevation is now available for the other models.
@rittels I forgot to mention that service ceiling climb rate (where normally aspirated engines loses their vertical performance down to around 100 ft/min) is also needed, so it will be 3 entries total for a climb phase:
vertical speed at sea level;
vertical speed at service ceiling;
and air speed.
In this case the final vertical speed (and thus, enroute time) will be dependent (calculated) on Min and Max values.
For example, if it set Max value to 500 ft/min (mean sea level) and Min value to 100 ft/min (e.g., at 16000 ft MSL) my vertical speed will be 400 ft/min at 4000 ft, 300 ft/min at 8000 ft etc.
The scale in the bottom right is an approximate scale that uses the standard height levels used in aviation like
950hPa / 2 000ft / 600m
850hPa / 5 000ft / 1500m
700hPa / 10 000ft / 3000m
300 hPa / 30 000 ft / 9000m
These are approximately equal and used for easy conversion between different unit. However they are not exact.
In fact heights of pressure levels changes with different weather conditions. eg cooler temps have pressure levels closer to the ground as the air is denser.
More info can be found here https://en.wikipedia.org/wiki/International_Standard_Atmosphere
Anyway the scale on the left is the model calculated height taking account of the meteo conditions (i think at least).
I am pretty sure that the scale on the windy map on the right is the correct values at the "model pressure height" which is an approximate height in m or feet.