[Therion] Depth seems to be including surface legs

We surveyed the surface above an old mine to get a feel for how thin the roof is. See attached Loch screenshot. Unfortunately, the surface legs are being included in the Depth value displayed on the Plan PDF (see attached). Displayed value is 13m, it should be about 8m. 13m is the maximum vertical extent of all our survey legs. The centerline data for the surface legs has been flagged as "flags surface". These have been correctly omitted from the cave length, and cave length is updated when the surface flag is commented out. However, the vertical range does not alter when the surface flag is toggled. I expected cave depth to be the maximum vertical range of the underground data. Hope someone can set me straight :) Duncan