Possible Clues:

• Delicacy; fine distinction
• Fine distinction
• Nuance, nicety
• Butler working endlessly in messy home shows refinement
• Delicately understated quality
• 'Nicety, nuance (8)'
• Finesse
• It's easy to miss
• It leaves Castle Adamant, for one, on time with variable refinement
• Delicate/refined quality