[USMC318ti]

I work at a car shop in Virginia, and we have put
Nitrous on nearly anything you can think of,
our rule of thumb is to never spray more than 50%
of your original HP, 200stock-100N2O, 150stock-75N2O.
So why do I never see anyone spraying more than
50-55 shots into the TI?
My nitrous kit is going on hopefully this week and we
are planning on spraying 70-75.
Anybody have a reason not to do this?
I run 92+ fuel, colder spark plugs, etc;