Also likely highly illegal:
91.1509 States the maximum hours achieved can be, 8 hours if single pilot, 10 if twin crew required.
Also:
(1) 500 hours in any calendar quarter;
(2) 800 hours in any two consecutive calendar quarters;
(3) 1,400 hours in any calendar year.
There are also limitations on duty time.
If the aircraft is operated under 135 or 121 then the hours are even more more restricted.
A desire to impress at this stage in a career will be taken advantage of - and sometimes to the detriment of the pilot involved. Many a pilot has been killed due to fatigue.
I would also question them, honestly how professional they consider themselves if they are operating the aircraft under such blatant unsafe conditions.