1.5v is the top voltage not the voltage you should even consider for everyday use and the cooling you're using may or may not allow even touching that high of a voltage.
You have headway if you want to go higher, if from both your posts your P95 is low 50s at 4.5ghz @ 1.28vcore.
I would suggest using your increases as a guide staying within the thermal throttling window, and go as high as you want staying below 1.45v to stay on the safe side.
But for 24/7 running stay below 1.4v, with your voltage reported at 4.5ghz you should easily be able to run 4.7 well within safe ranges with no problem.
Even though I can run 5.0ghz stable, (CPU-Z Validation Below), I have no intentions of running that voltage 24/7!
I run 4.5ghz 24/7, as it accomplishes everything I do so well, running any higher just is not necessary.
But FYI I've clocked in stable at, 46x, 47x, 48x, 49x, and 50x.