Manual route sections: no elevation loss/gain

[herve.caf]

Hi all,
When planning a route in the web planner, if a route section is drawn manually (instead of e.g. "Walking") on off-track areas of the map: the distance is updated, but not the elevation loss/gain.
I assume this is because there is no "known track" on these sections, but couldn't the elevation change information be derived from the DTM?