Regardless of weather presets, scripting call 'weather.clouds.thickness' always reports the same thickness of 656ft!?

[TEMPEST.114]

I'm using the following in my ATIS script

  local weather       = env.mission.weather

  local cloudCover    = api.TUC.GetCloudCoverAsString(false)

  local cloudBase     = api.TUC.MetresToFeet(weather.clouds.base)

  local thickness     = api.TUC.MetresToFeet(weather.clouds.thickness)

  local visibility    = weather.visibility.distance

  local fogThickness  = api.TUC.MetresToFeet(weather.fog.thickness)

  local fogVisibility = weather.fog.visibility

  local dustDensity   = api.TUC.MetresToFeet(weather.dust_density)

Everything looks okay except that the THICKNESS which I'm led to believe from the documentation on hoggitworld is for the lowest cloudbase, ALWAYS reports the same amount of 656ft, regardless of the weather preset used and how thick the cloudbase is to fly through.

Am I using this correctly or is this a bug?