Possible Clues:

• Awkward to do then with precision
• At exactly the right time
• Sharp tot, honed to become exceptional
• 'Punctually on punctuation (2,3,3)'
• At exactly the right time, then, to do otherwise
• Just over half the normal place for signature? Precisely!
• Is this an example of time conscious study of nanotechnology?
• The sentence ends precisely then and there
• At precisely the right time
• Absolutely punctual