How to Sous Vide Lamb says:
Blade Chop: Medium-Rare: 131°F for 18 to 24 Hours (55.0ºC)
Shoulder: Medium-Rare: 131°F for 1 to 2 Days (55.0ºC)
132°F for 2 hours
I know sous vide is very forgiving with cooking times, but there is a big difference between 2 hours and 24 hours that can't be accounted for by the 1C° temperature difference.
I would expect at least one of these to be a bad idea, but which one?