The Primary Heat exchangerWhat's a HEX?
Thought a PRV only leaks through the copper overflow?
.... Yup, it does, the OP has mentioned 2 areas where the system is dripping from, one from the condensate and one from the PRV outlet, put a bag over that outlet will show that the PRV is passing and how much water it is letting by, it could be down to a bad EV. The condensate is another issue and could indicate a pinholed HEX if it keeps dripping all the time.