Referencing Support Ticket: 3012
It became apparent through the support ticket referenced above that whenever a field has a lookup table assigned to it that it automatically add zLegacy fields for that field no matter how they are mapped (as xRef or not). These lookup tables are added through the system type and should be there, but the zLegacy storage of the original value is unnecessary unless the field is mapped to be an xRef. By default that means all fields in all SAP tables with lookup tables get zLegacy fields added and that these cannot be deleted or inactivated without removing the lookup table reference. The field can be deleted or inactivated but will be reactivated or recreated upon sync to map.
Please remove the auto-zLegacy addition for fields with lookup tables assigned.