Sample command:
**getSurfaceHeight //position//**
Position: positionASL - the position where surface height is needed
If possible, maybe a companion command **getSurfaceNormal //position// **can also be helpful. (which returns the walkable surface normal at a 3D positionASL, not necessarily terrain normal like surfaceNormal)
Alternatively, you can update the **lineIntersectsSurfaces** command to support the "roadWay" lod as well.