Best Practices:

• Using NCOPY can be especially beneficial in complex drawings where maintaining block structures is crucial. It provides a way to duplicate specific instances of nested blocks without modifying the original block definition. Always exercise care when making modifications to avoid unintended changes to your drawing.

• Identify source clearly: Ensure you’re selecting objects from the correct xref, block, or underlay.
• Check for nested blocks: If the nested object contains nested blocks, NCOPY might not copy them as expected. Consider exploding those nested blocks first.
• Maintain object properties: NCOPY generally preserves object properties like layers, colors, and linetypes.
• Control visibility: To avoid unwanted visual clutter, turn off the visibility of the xref or block after copying the desired objects.
• Consider alternatives: For complex copying tasks involving multiple nested objects or intricate relationships, explore other commands like REFEDIT or BLOCKEDIT, which offer more comprehensive editing capabilities within xrefs and blocks.

Additional Tips:

• Use grips: After copying, use grips to adjust the position and orientation of the copied objects.

• Combine with other commands: Integrate NCOPY with other editing commands like MOVE, ROTATE, or SCALE for further refinement.