Reply To: Started PEP at around hour 60. Is that too late for it to work?

You are inside the window. 72 hours is the outer limit in the guidance, not a point where it suddenly stops working, and 60 is inside it.

It is fair to say sooner is better, which is why services treat it as urgent. But you did get there, and being at hour 60 rather than hour 12 does not mean it will not work.