It is said anything over 1,000hrs of SEP time is worthless, and yes it might be, but this doesn't mean you can't go beyond this, does it matter if you had 5,000hrs SEP time?
Well, in my current job I got into a higher pay scale (by some 5k pa) and a better sector pay system because of the amount of P.1 time I had on joining. A lot of these P.1 hours were SEP and accumulated through instructing.
P.1 hours will never do you harm.