Methods of additively printing an extension segment on a workpiece may include pretreating a workpiece-interface of a workpiece using an energy beam from an additive manufacturing machine, providing a pretreated workpiece-interface having received a pretreatment, with the pretreatment remediating an aberrant feature of the workpiece and/or the workpiece-interface. Such methods may additionally include additively printing an extension segment on the pretreated workpiece-interface using the energy beam from the additive manufacturing machine. Exemplary additive manufacturing system for printing an extension segment on a workpiece may include a controller operably coupled to a vision system and an additive manufacturing machine.