FileReadOptionsScaleGeometry Property

true: If ImportMode is true and the geometry in the file being read has a unit system different from the model's unit system, then apply the unit conversion scale to the file's geometry before adding it to the model.

false: Do not scale. Once case where this happens is when an instance definition is read from a file and the model space instance references have been scaled. In case the instance definition geometry cannot be scaled or the net result is that the size of the instance reference object is scaled by the square of the scale factor.