public string UnpackOtherLocation {get; set;}

//UnpackOther settings control unpacking of anything _other than_
//a ppkx or aptx. Options are mutually exclusive.

//Set ApplicationOptions.DownloadOptions.UnpackOtherLocation explicitly to
//toggle ApplicationOptions.DownloadOptions.AskForUnpackOtherLocation and
//ApplicationOptions.DownloadOptions.UnpackOtherToProjectLocation to false
//Note: default is typically <My Documents>\ArcGIS\Packages, _not_ null.
//This is the same behavior as on the Pro UI.
ApplicationOptions.DownloadOptions.UnpackOtherLocation = @"D:\data\for_other";

//or...to use a location already stored in UnpackOtherLocation as the
//default without changing it, 
//set ApplicationOptions.DownloadOptions.AskForUnpackOtherLocation and
//ApplicationOptions.DownloadOptions.UnpackOtherToProjectLocation to false
//explicitly. This is the same behavior as on the Pro UI.
if (!string.IsNullOrEmpty(ApplicationOptions.DownloadOptions.UnpackOtherLocation))
{
  ApplicationOptions.DownloadOptions.AskForUnpackOtherLocation = false;
  ApplicationOptions.DownloadOptions.UnpackOtherToProjectLocation = false;
}

//Setting ApplicationOptions.DownloadOptions.AskForUnpackOtherLocation to
//true overrides any UnpackOtherLocation value and sets 
//ApplicationOptions.DownloadOptions.UnpackOtherToProjectLocation to false.
//This is the same behavior as on the Pro UI.
ApplicationOptions.DownloadOptions.AskForUnpackOtherLocation = true;

//Setting ApplicationOptions.DownloadOptions.UnpackOtherToProjectLocation to
//true overrides any UnpackOtherLocation value and sets 
//ApplicationOptions.DownloadOptions.AskForUnpackOtherLocation to false.
//This is the same behavior as on the Pro UI.
ApplicationOptions.DownloadOptions.UnpackOtherToProjectLocation = false;