Hi Ankie,
you can't update two units (one EA from Kf1 and another EA from KF2 ) to 0unit (one column) in DSO.
even if you opt for unit conversion you need to have another column to update those values. Like wise, if there is no unit for Kf2 in DSO, same is updated to cube (empty unit from kf2).
may be this is achievable by inserting a new line to update Kf2 and its unit from a routine by unit conversion (ex: using FM -->unit_conversion_simple). but this would be bit complex.