Article 15 is very clear that there is no carence time for employing a PRRC under MDR. In fact, you need one from the beginning! In addition, the PRRC must be registered in the EUDAMED (since EUDAMED is not operational yet, this is on hold) or another, local (on country level) register, e.g. in Germany the DIMDI.
On a member state level, i.e. country level, fines can be defined in the national legislation which not seldom reach Euro 30’000.00 per case.