ok, I removed any mod and with 12V ouput, ADC voltage is 3.1V. Installed the new voltage mod according to reply#8 by ubrain user, and the 22k resistor from adc pin 24 to ground and with 3.3V @13.8V ouput no OVP issue varing voltage up to 14.54V (max available).
Don't have power resistor to perform test with high current but I will test on field with my transceivers requiring more than 20A (yes, you're right I'm an ham!), eventually changing the resistor to raise the OVP, but quite sure that it's ok yet.
About the rf noise, it depends on several fators, equipments, frequencies used etc. usually a common mode filter wounded on ferrite on the ouput could help with conducted emi in hf or low vhf range. A ripple up to 100mV is easily visible with oscillocope on the output and also high frequency noise unfortunately; this is a drawback of these items, but I have not understood if it's due to a poor filters to reduce ripple and hf nosie (not need for application they are designed for) or due to a circuit design topology. I have seen similar issue on my dps-600 power supply.
I attach a couple of images to help any PL12 owner that need to perferm the mod (of course I don't take any responsability for the mod, people need to know that these power supplies can be very dangerous items!)
I would like to use a quieter fan, anybody know the pinout of the 4 wire pwm connector?