I've recently received my OrangePi Zero v1.4 and have experienced the same heat issue. After some experimentation I noticed that while the chip idles really, really hot (65C or so even with heatsink and thermal paste) when under load it barely budges (rises to about 75-80C a delta of 10-15C), this suggests that the DVFS may be broken on the new board revision. Maybe with the regulator changes it has affected how you set the resistor network? Just a wild guess.
BTW on mainline kernel it idles around a reasonable 45C or so at room temp.