I guess the question of OT or not to OT is always subjective. Quoting the Movie - "A Spoonful of Sugar .......
IMO it would be useful to offer a specific SOP for yr boss. Something like - "Use of Thermometer Calibration Certificate Data". Might ensure less head scratching in 1 years time.
Curiously, i tried to find just one reference/example to support adding the Certificate's Uncertainty Factor to the Critical Limit in the IT Food Literature and (so far) failed. Anyone ?.