For the Instrument entity type, the project defaults ZS_AB_AGR (for the default attribute group) and ZS_AB_UNIT (for the default attribute unit) should be set. These values are looked up, even if they are not needed. If you insert the Hookup entity type, the assembly positions inherit the tag number from the assembly header and become ItemType SWT=Standard with Tag. To allow import of tagged material with quantities greater than one, set the ZB_TAGQTY to 'N', preventing OMI from rejecting those records.