Okay being actually serious, Lumi does grind he hardest in the agency, not to mention doing background work for the company and also working on her music, with Tenma's 10-hour gorillas being a solid runner-up. Not everyone can keep that kind of pace, nor should they.
But i have been consistently somewhat-concerned over Pippa often getting actually tired at the end of her 3-hour standard time - like, considering this is, in fact, her actual full-time job, one'd think her batteries for it would be a bit stronger.